Friday, June 29, 2012

What are the Software QA and Testing Frequently-Asked-Questions?

What is 'Software Quality Assurance'?
Software QA involves the entire software development PROCESS - monitoring and improving the process, making sure that any agreed-upon standards and procedures are followed, and ensuring that problems are found and dealt with. It is oriented to 'prevention'. (See the Bookstore section's 'Software QA' category for a list of useful books on Software Quality Assurance.)

What is 'Software Testing'?
Testing involves operation of a system or application under controlled conditions and evaluating the results (eg, 'if the user is in interface A of the application while using hardware B, and does C, then D should happen'). The controlled conditions should include both normal and abnormal conditions. Testing should intentionally attempt to make things go wrong to determine if things happen when they shouldn't or things don't happen when they should. It is oriented to 'detection'. (See the Bookstore section's 'Software Testing' category for a list of useful books on Software Testing.)
  • Organizations vary considerably in how they assign responsibility for QA and testing. Sometimes they're the combined responsibility of one group or individual. Also common are project teams that include a mix of testers and developers who work closely together, with overall QA processes monitored by project managers. It will depend on what best fits an organization's size and business structure.

  • In March of 2012 the Initial Public Offering of the stock of a new stock exchange was cancelled due to software bugs in their trading platform that interfered with trading in stocks including their own IPO stock, according to media reports. The high-speed trading platform reportedly was already handling more than 10 percent of all trading in U.S. securites, but the procesing of initial IPO trading was new for the system, and though it had undergone testing, it was unable to properly handle the IPO initial trades. The problem also briefly affected trading of other stocks and other stock exchanges.
  • It was reported that software problems in an automated highway toll charging system caused erroneous charges to thousands of customers in a short period of time in December 2011.
  • In August 2011, a major North American retailer initiated its own online e-commerce website, after contracting it out for many years. It was reported that within the first few months the site crashed six times, home page links were found not to work, gift registries were reported not working properly, and the online division's president left the company.
  • A new U.S.-government-run credit card complaint handling system was not working correctly according to August 2011 news reports. Banks were required to respond to complaints routed to them from the system, but due to system bugs the complaints were not consistently being routed to companies as expected. Reportedly the system had not been properly tested.
  • News reports in Asia in July of 2011 reported that software bugs in a national computerized testing and grading system resulted in incorrect test results for tens of thousands of high school students. The national education ministry had to reissue grade reports to nearly 2 million students nationwide.
  • In April of 2011 bugs were found in popular smartphone software that resulted in long-term data storage on the phone that could be utilized in location tracking of the phone, even when it was believed that locator services in the phone were turned off. A software update was released several weeks later which was expected to resolve the issues.
  • Software problems in a new software upgrade for farecards in a major urban transit system reportedly resulted in a loss of a half million dollars before the software was fixed, according to October 2010 news reports.
  • In October of 2010 a large municipality's new web-based election voting system was opened to the public for a testing period in which users were invited to attempt to break it. Within a few days the site was penetrated by college student hackers and its functionality altered.
  • A smartphone online banking application was reported in July 2010 to have a security bug affecting more than 100,000 customers. Users were able to upgrade to a newer software version that fixed the problem.
  • In July 2010 a major smartphone maker reported that their software contained a long-time bug that resulted in incorrect indicators of signal strength in the phone's interface. Reportedly customers had been complaining about the problem for several years. The company provided a fix for the problem several weeks later.
  • News reports in April 2010 indicated that a major antivirus software vendor provided a faulty signature update file which caused computers to crash, continuously reboot, or lose network connectivity. This was reportedly due to a problematical change in the vendor's testing process. Stories of affected systems included police departments reduced to hand-written reports, hospitals turning away patients, and closing of supermarkets.
  • A major auto manufacturer was reported to have found that a software problem was the cause of vehicle braking delayed reactions in one of its popular models, according to February 2010 media reports.
  • Email services of a major smartphone system were interrupted or unavailable for nine hours in December 2009, the second service interruption within a week, according to news reports. The problems were believed to be due to bugs in new versions of the email system software.
  • It was reported in August 2009 that a large suburban school district introduced a new computer system that was 'plagued with bugs' and resulted in many students starting the school year without schedules or with incorrect schedules, and many problems with grades. Upset students and parents started a social networking site for sharing complaints.
  • In February of 2009 users of a major search engine site were prevented from clicking through to sites listed in search results for part of a day. It was reportedly due to software that did not effectively handle a mistakenly-placed "/" in an internal ancillary reference file that was frequently updated for use by the search engine. Users, instead of being able to click thru to listed sites, were instead redirected to an intermediary site which, as a result of the suddenly enormous load, was rendered unusable.
  • A large health insurance company was reportedly banned by regulators from selling certain types of insurance policies in January of 2009 due to ongoing computer system problems that resulted in denial of coverage for needed medications and mistaken overcharging or cancelation of benefits. The regulatory agency was quoted as stating that the problems were posing "a serious threat to the health and safety" of beneficiaries.
  • A news report in January 2009 indicated that a major IT and management consulting company was still battling years of problems in implementing its own internal accounting systems, including a 2005 implementation that reportedly "was attempted without adequate testing".
  • In August of 2008 it was reported that more than 600 U.S. airline flights were significantly delayed due to a software glitch in the U.S. FAA air traffic control system. The problem was claimed to be a 'packet switch' that 'failed due to a database mismatch', and occurred in the part of the system that handles required flight plans.
  • Software system problems at a large health insurance company in August 2008 were the cause of a privacy breach of personal health information for several hundred thousand customers, according to news reports. It was claimed that the problem was due to software that 'was not comprehensively tested'.
  • A major clothing retailer was reportedly hit with significant software and system problems when attempting to upgrade their online retailing systems in June 2008. Problems remained ongoing for some time. When the company made their public quarterly financial report, the software and system problems were claimed as the cause of the poor financial results.
  • Software problems in the automated baggage sorting system of a major airport in February 2008 prevented thousands of passengers from checking baggage for their flights. It was reported that the breakdown occurred during a software upgrade, despite pre-testing of the software. The system continued to have problems in subsequent months.
  • News reports in December of 2007 indicated that significant software problems were continuing to occur in a new ERP payroll system for a large urban school system. It was believed that more than one third of employees had received incorrect paychecks at various times since the new system went live the preceding January, resulting in overpayments of $53 million, as well as underpayments. An employees' union brought a lawsuit against the school system, the cost of the ERP system was expected to rise by 40%, and the non-payroll part of the ERP system was delayed. Inadequate testing reportedly contributed to the problems. The school system was still working on cleaning up the aftermath of the problems in December 2009, going so far as to bring lawsuits against some employees to get them to return overpayments.
  • In November of 2007 a regional government reportedly brought a multi-million dollar lawsuit against a software services vendor, claiming that the vendor 'minimized quality' in delivering software for a large criminal justice information system and the system did not meet requirements. The vendor also sued its subcontractor on the project.
  • In June of 2007 news reports claimed that software flaws in a popular online stock-picking contest could be used to gain an unfair advantage in pursuit of the game's large cash prizes. Outside investigators were called in and in July the contest winner was announced. Reportedly the winner had previously been in 6th place, indicating that the top 5 contestants may have been disqualified.
  • A software problem contributed to a rail car fire in a major underground metro system in April of 2007 according to newspaper accounts. The software reportedly failed to perform as expected in detecting and preventing excess power usage in equipment on new passenger rail cars, resulting in overheating and fire in the rail car, and evacuation and shutdown of part of the system.
  • Tens of thousands of medical devices were recalled in March of 2007 to correct a software bug. According to news reports, the software would not reliably indicate when available power to the device was too low.
  • A September 2006 news report indicated problems with software utilized in a state government's primary election, resulting in periodic unexpected rebooting of voter checkin machines, which were separate from the electronic voting machines, and resulted in confusion and delays at voting sites. The problem was reportedly due to insufficient testing.
  • In August of 2006 a U.S. government student loan service erroneously made public the personal data of as many as 21,000 borrowers on it's web site, due to a software error. The bug was fixed and the government department subsequently offered to arrange for free credit monitoring services for those affected.
  • A software error reportedly resulted in overbilling of up to several thousand dollars to each of 11,000 customers of a major telecommunications company in June of 2006. It was reported that the software bug was fixed within days, but that correcting the billing errors would take much longer.
  • News reports in May of 2006 described a multi-million dollar lawsuit settlement paid by a healthcare software vendor to one of its customers. It was reported that the customer claimed there were problems with the software they had contracted for, including poor integration of software modules, and problems that resulted in missing or incorrect data used by medical personnel.
  • In early 2006 problems in a government's financial monitoring software resulted in incorrect election candidate financial reports being made available to the public. The government's election finance reporting web site had to be shut down until the software was repaired.
  • Trading on a major Asian stock exchange was brought to a halt in November of 2005, reportedly due to an error in a system software upgrade. The problem was rectified and trading resumed later the same day.
  • A May 2005 newspaper article reported that a major hybrid car manufacturer had to install a software fix on 20,000 vehicles due to problems with invalid engine warning lights and occasional stalling. In the article, an automotive software specialist indicated that the automobile industry spends $2 billion to $3 billion per year fixing software problems.
  • Media reports in January of 2005 detailed severe problems with a $170 million high-profile U.S. government IT systems project. Software testing was one of the five major problem areas according to a report of the commission reviewing the project. In March of 2005 it was decided to scrap the entire project.
  • In July 2004 newspapers reported that a new government welfare management system in Canada costing several hundred million dollars was unable to handle a simple benefits rate increase after being put into live operation. Reportedly the original contract allowed for only 6 weeks of acceptance testing and the system was never tested for its ability to handle a rate increase.
  • Millions of bank accounts were impacted by errors due to installation of inadequately tested software code in the transaction processing system of a major North American bank, according to mid-2004 news reports. Articles about the incident stated that it took two weeks to fix all the resulting errors, that additional problems resulted when the incident drew a large number of e-mail phishing attacks against the bank's customers, and that the total cost of the incident could exceed $100 million.
  • A bug in site management software utilized by companies with a significant percentage of worldwide web traffic was reported in May of 2004. The bug resulted in performance problems for many of the sites simultaneously and required disabling of the software until the bug was fixed.
  • According to news reports in April of 2004, a software bug was determined to be a major contributor to the 2003 Northeast blackout, the worst power system failure in North American history. The failure involved loss of electrical power to 50 million customers, forced shutdown of 100 power plants, and economic losses estimated at $6 billion. The bug was reportedly in one utility company's vendor-supplied power monitoring and management system, which was unable to correctly handle and report on an unusual confluence of initially localized events. The error was found and corrected after examining millions of lines of code.
  • In early 2004, news reports revealed the intentional use of a software bug as a counter-espionage tool. According to the report, in the early 1980's one nation surreptitiously allowed a hostile nation's espionage service to steal a version of sophisticated industrial software that had intentionally-added flaws. This eventually resulted in major industrial disruption in the country that used the stolen flawed software.
  • A major U.S. retailer was reportedly hit with a large government fine in October of 2003 due to web site errors that enabled customers to view one another's online orders.
  • News stories in the fall of 2003 stated that a manufacturing company recalled all their transportation products in order to fix a software problem causing instability in certain circumstances. The company found and reported the bug itself and initiated the recall procedure in which a software upgrade fixed the problems.
  • In August of 2003 a U.S. court ruled that a lawsuit against a large online brokerage company could proceed; the lawsuit reportedly involved claims that the company was not fixing system problems that sometimes resulted in failed stock trades, based on the experiences of 4 plaintiffs during an 8-month period. A previous lower court's ruling that "...six miscues out of more than 400 trades does not indicate negligence." was invalidated.
  • In April of 2003 it was announced that a large student loan company in the U.S. made a software error in calculating the monthly payments on 800,000 loans. Although borrowers were to be notified of an increase in their required payments, the company will still reportedly lose $8 million in interest. The error was uncovered when borrowers began reporting inconsistencies in their bills.
  • News reports in February of 2003 revealed that the U.S. Treasury Department mailed 50,000 Social Security checks without any beneficiary names. A spokesperson indicated that the missing names were due to an error in a software change. Replacement checks were subsequently mailed out with the problem corrected, and recipients were then able to cash their Social Security checks.
  • It was reported that in April 2002, problems with the integration of several merged bank systems in Japan resulted in millions of errors in ATM transactions, automatic bill payments errors, delayed debits, duplicate debits, and other problems. Reportedly the problems were caused by a delay in the start of the systems integration work and subsequent inadequate testing, and it took more than a month to restore banking operations to normal
  • In March of 2002 it was reported that software bugs in Britain's national tax system resulted in more than 100,000 erroneous tax overcharges. The problem was partly attributed to the difficulty of testing the integration of multiple systems.
  • A newspaper columnist reported in July 2001 that a serious flaw was found in off-the-shelf software that had long been used in systems for tracking certain U.S. nuclear materials. The same software had been recently donated to another country to be used in tracking their own nuclear materials, and it was not until scientists in that country discovered the problem, and shared the information, that U.S. officials became aware of the problems.
  • According to newspaper stories in mid-2001, a major systems development contractor was fired and sued over problems with a large retirement plan management system. According to the reports, the client claimed that system deliveries were late, the software had excessive defects, and it caused other systems to crash.
  • In January of 2001 newspapers reported that a major European railroad was hit by the aftereffects of the Y2K bug. The company found that many of their newer trains would not run due to their inability to recognize the date '31/12/2000'; the trains were started by altering the control system's date settings.
  • News reports in September of 2000 told of a software vendor settling a lawsuit with a large mortgage lender; the vendor had reportedly delivered an online mortgage processing system that did not meet specifications, was delivered late, and didn't work.
  • In early 2000, major problems were reported with a new computer system in a large suburban U.S. public school district with 100,000+ students; problems included 10,000 erroneous report cards and students left stranded by failed class registration systems; the district's CIO was fired. The school district decided to reinstate it's original 25-year old system for at least a year until the bugs were worked out of the new system by the software vendors.
  • A review board concluded that the NASA Mars Polar Lander failed in December 1999 due to software problems that caused improper functioning of retro rockets utilized by the Lander as it entered the Martian atmosphere.
  • In October of 1999 the $125 million NASA Mars Climate Orbiter spacecraft was believed to be lost in space due to a simple data conversion error. It was determined that spacecraft software used certain data in English units that should have been in metric units. Among other tasks, the orbiter was to serve as a communications relay for the Mars Polar Lander mission, which failed for unknown reasons in December 1999. Several investigating panels were convened to determine the process failures that allowed the error to go undetected.
  • Bugs in software supporting a large commercial high-speed data network affected 70,000 business customers over a period of 8 days in August of 1999. Among those affected was the electronic trading system of the largest U.S. futures exchange, which was shut down for most of a week as a result of the outages.
  • In April of 1999 a software bug caused the failure of a $1.2 billion U.S. military satellite launch, the costliest unmanned accident in the history of Cape Canaveral launches. The failure was the latest in a string of launch failures, triggering a complete military and industry review of U.S. space launch programs, including software integration and testing processes. Congressional oversight hearings were requested.
  • A small town in Illinois in the U.S. received an unusually large monthly electric bill of $7 million in March of 1999. This was about 700 times larger than its normal bill. It turned out to be due to bugs in new software that had been purchased by the local power company to deal with Y2K software issues.
  • In early 1999 a major computer game company recalled all copies of a popular new product due to software problems. The company made a public apology for releasing a product before it was ready.
  • The computer system of a major online U.S. stock trading service failed during trading hours several times over a period of days in February of 1999 according to nationwide news reports. The problem was reportedly due to bugs in a software upgrade intended to speed online trade confirmations.
  • In April of 1998 a major U.S. data communications network failed for 24 hours, crippling a large part of some U.S. credit card transaction authorization systems as well as other large U.S. bank, retail, and government data systems. The cause was eventually traced to a software bug.
  • January 1998 news reports told of software problems at a major U.S. telecommunications company that resulted in no charges for long distance calls for a month for 400,000 customers. The problem went undetected until customers called up with questions about their bills.
  • In November of 1997 the stock of a major health industry company dropped 60% due to reports of failures in computer billing systems, problems with a large database conversion, and inadequate software testing. It was reported that more than $100,000,000 in receivables had to be written off and that multi-million dollar fines were levied on the company by government agencies.
  • A retail store chain filed suit in August of 1997 against a transaction processing system vendor (not a credit card company) due to the software's inability to handle credit cards with year 2000 expiration dates.
  • In August of 1997 one of the leading consumer credit reporting companies reportedly shut down their new public web site after less than two days of operation due to software problems. The new site allowed web site visitors instant access, for a small fee, to their personal credit reports. However, a number of initial users ended up viewing each others' reports instead of their own, resulting in irate customers and nationwide publicity. The problem was attributed to "...unexpectedly high demand from consumers and faulty software that routed the files to the wrong computers."
  • In November of 1996, newspapers reported that software bugs caused the 411 telephone information system of one of the U.S. RBOC's to fail for most of a day. Most of the 2000 operators had to search through phone books instead of using their 13,000,000-listing database. The bugs were introduced by new software modifications and the problem software had been installed on both the production and backup systems. A spokesman for the software vendor reportedly stated that 'It had nothing to do with the integrity of the software. It was human error.'
  • On June 4 1996 the first flight of the European Space Agency's new Ariane 5 rocket failed shortly after launching, resulting in an estimated uninsured loss of a half billion dollars. It was reportedly due to the lack of exception handling of a floating-point error in a conversion from a 64-bit integer to a 16-bit signed integer.
  • Software bugs caused the bank accounts of 823 customers of a major U.S. bank to be credited with $924,844,208.32 each in May of 1996, according to newspaper reports. The American Bankers Association claimed it was the largest such error in banking history. A bank spokesman said the programming errors were corrected and all funds were recovered.
  • In August 1991 the concrete base structure for a North Sea oil platform imploded and sank off the coast of Norway, reportedly due to errors in initially-used design software. The enormous structure, on hitting the seabed, reportedly was detected as a magnitude 3.0 seismic event and resulted in a loss of $700 million. The base structure was eventually redesigned and the full platform was completed two years later, and was still in use as of 2008.
  • On January 1 1984 all computers produced by one of the leading minicomputer makers of the time reportedly failed worldwide. The cause was claimed to be a leap year bug in a date handling function utilized in deletion of temporary operating system files. Technicians throughout the world worked for several days to clear up the problem. It was also reported that the same bug affected many of the same computers four years later.
  • Software bugs in a Soviet early-warning monitoring system nearly brought on nuclear war in 1983, according to news reports in early 1999. The software was supposed to filter out false missile detections caused by Soviet satellites picking up sunlight reflections off cloud-tops, but failed to do so. Disaster was averted when a Soviet commander, based on what he said was a '...funny feeling in my gut', decided the apparent missile attack was a false alarm. The filtering software code was rewritten.
For more lists of software bugs see 'Collection of Software Bugs', a large collection of bugs and links to other bug lists maintained by Prof. Thomas Huckle at the Institut für Informatik in Germany, and a 'List of software bugs' in various categories maintained on Wikipedia.

Does every software project need testers?
While all projects will benefit from testing, some projects may not require independent test staff to succeed.
Which projects may not need independent test staff? The answer depends on the size and context of the project, the risks, the development methodology, the skill and experience of the developers, and other factors. For instance, if the project is a short-term, small, low risk project, with highly experienced programmers utilizing thorough unit testing or test-first development, then test engineers may not be required for the project to succeed.
In some cases an IT organization may be too small or new to have a testing staff even if the situation calls for it. In these circumstances it may be appropriate to instead use contractors or outsourcing, or adjust the project management and development approach (by switching to more senior developers and agile test-first development, for example). Inexperienced managers sometimes gamble on the success of a project by skipping thorough testing or having programmers do post-development functional testing of their own work, a decidedly high risk gamble.
For non-trivial-size projects or projects with non-trivial risks, a testing staff is usually necessary. As in any business, the use of personnel with specialized skills enhances an organization's ability to be successful in large, complex, or difficult tasks. It allows for both a) deeper and stronger skills and b) the contribution of differing perspectives. For example, programmers typically have the perspective of 'what are the technical issues in making this functionality work?'. A test engineer typically has the perspective of 'what might go wrong with this functionality, and how can we ensure it meets expectations?'. A technical person who can be highly effective in approaching tasks from both of those perspectives is rare, which is why, sooner or later, organizations bring in test specialists.

  • miscommunication or no communication - as to specifics of what an application should or shouldn't do (the application's requirements).
  • software complexity - the complexity of current software applications can be difficult to comprehend for anyone without experience in modern-day software development. Multi-tier distributed systems, applications utilizing multiple local and remote web services applications, data communications, enormous relational databases, security complexities, and sheer size of applications have all contributed to the exponential growth in software/system complexity.
  • programming errors - programmers, like anyone else, can make mistakes.
  • changing requirements (whether documented or undocumented) - the end-user may not understand the effects of changes, or may understand and request them anyway - redesign, rescheduling of engineers, effects on other projects, work already completed that may have to be redone or thrown out, hardware requirements that may be affected, etc. If there are many minor changes or any major changes, known and unknown dependencies among parts of the project are likely to interact and cause problems, and the complexity of coordinating changes may result in errors. Enthusiasm of engineering staff may be affected. In some fast-changing business environments, continuously modified requirements may be a fact of life. In this case, management must understand the resulting risks, and QA and test engineers must adapt and plan for continuous extensive testing to keep the inevitable bugs from running out of control - see 'What can be done if requirements are changing continuously?' in the LFAQ. Also see information about 'agile' approaches such as XP, in Part 2 of the FAQ.
  • time pressures - scheduling of software projects is difficult at best, often requiring a lot of guesswork. When deadlines loom and the crunch comes, mistakes will be made.
  • egos - people prefer to say things like:
    'no problem' 
      'piece of cake'
      'I can whip that out in a few hours'
      'it should be easy to update that old code'
     instead of:
      'that adds a lot of complexity and we could end up
         making a lot of mistakes'
      'we have no idea if we can do that; we'll wing it'
      'I can't estimate how long it will take, until I
         take a close look at it'
      'we can't figure out what that old spaghetti code
         did in the first place'
     If there are too many unrealistic 'no problem's', the
     result is bugs.
  • poorly documented code - it's tough to maintain and modify code that is badly written or poorly documented; the result is bugs. In many organizations management provides no incentive for programmers to document their code or write clear, understandable, maintainable code. In fact, it's usually the opposite: they get points mostly for quickly turning out code, and there's job security if nobody else can understand it ('if it was hard to write, it should be hard to read').
  • software development tools - visual tools, class libraries, compilers, scripting tools, etc. often introduce their own bugs or are poorly documented, resulting in added bugs.

  • A lot depends on the size of the organization and the risks involved. For large organizations with high-risk (in terms of lives or property) projects, serious management buy-in is required and a formalized QA process is necessary.
  • Where the risk is lower, management and organizational buy-in and QA implementation may be a slower, step-at-a-time process. QA processes should be balanced with productivity so as to keep bureaucracy from getting out of hand.
  • For small groups or projects, a more ad-hoc process may be appropriate, depending on the type of customers and projects. A lot will depend on team leads or managers, feedback to developers, and ensuring adequate communications among customers, managers, developers, and testers.
  • The most value for effort will often be in (a) requirements management processes, with a goal of clear, complete, testable requirement specifications embodied in requirements or design documentation, or in 'agile'-type environments extensive continuous coordination with end-users, (b) design inspections and code inspections, and (c) post-mortems/retrospectives.
  • Other possibilities include incremental self-managed team approaches such as 'Kaizen' methods of continuous process improvement, the Deming-Shewhart Plan-Do-Check-Act cycle, and others.
Also see 'How can QA processes be implemented without reducing productivity?' in the LFAQ section. (See the Bookstore section's 'Software QA', 'Software Engineering', and 'Project Management' categories for useful books with more information.)

What is verification? validation?
Verification typically involves reviews and meetings to evaluate documents, plans, code, requirements, and specifications. This can be done with checklists, issues lists, walkthroughs, and inspection meetings. Validation typically involves actual testing and takes place after verifications are completed. The term 'IV & V' refers to Independent Verification and Validation.

What is a 'walkthrough'?
A 'walkthrough' is an informal meeting for evaluation or informational purposes. Little or no preparation is usually required.

What's an 'inspection'?
An inspection is more formalized than a 'walkthrough', typically with 3-8 people including a moderator, reader, and a recorder to take notes. The subject of the inspection is typically a document such as a requirements spec or a test plan, and the purpose is to find problems and see what's missing, not to fix anything. Attendees should prepare for this type of meeting by reading thru the document; most problems will be found during this preparation. The result of the inspection meeting should be a written report. Thorough preparation for inspections is difficult, painstaking work, but is one of the most cost effective methods of ensuring quality. Employees who are most skilled at inspections are like the 'eldest brother' in the parable in 'Why is it often hard for organizations to get serious about quality assurance?'. Their skill may have low visibility but they are extremely valuable to any software development organization, since bug prevention is far more cost-effective than bug detection.

  • Black box testing - not based on any knowledge of internal design or code. Tests are based on requirements and functionality.
  • White box testing - based on knowledge of the internal logic of an application's code. Tests are based on coverage of code statements, branches, paths, conditions.
  • unit testing - the most 'micro' scale of testing; to test particular functions or code modules. Typically done by the programmer and not by testers, as it requires detailed knowledge of the internal program design and code. Not always easily done unless the application has a well-designed architecture with tight code; may require developing test driver modules or test harnesses.
  • incremental integration testing - continuous testing of an application as new functionality is added; requires that various aspects of an application's functionality be independent enough to work separately before all parts of the program are completed, or that test drivers be developed as needed; done by programmers or by testers.
  • integration testing - testing of combined parts of an application to determine if they function together correctly. The 'parts' can be code modules, individual applications, client and server applications on a network, etc. This type of testing is especially relevant to client/server and distributed systems.
  • functional testing - black-box type testing geared to functional requirements of an application; this type of testing should be done by testers. This doesn't mean that the programmers shouldn't check that their code works before releasing it (which of course applies to any stage of testing.)
  • system testing - black-box type testing that is based on overall requirements specifications; covers all combined parts of a system.
  • end-to-end testing - similar to system testing; the 'macro' end of the test scale; involves testing of a complete application environment in a situation that mimics real-world use, such as interacting with a database, using network communications, or interacting with other hardware, applications, or systems if appropriate.
  • sanity testing or smoke testing - typically an initial testing effort to determine if a new software version is performing well enough to accept it for a major testing effort. For example, if the new software is crashing systems every 5 minutes, bogging down systems to a crawl, or corrupting databases, the software may not be in a 'sane' enough condition to warrant further testing in its current state.
  • regression testing - re-testing after fixes or modifications of the software or its environment. It can be difficult to determine how much re-testing is needed, especially near the end of the development cycle. Automated testing approaches can be especially useful for this type of testing.
  • acceptance testing - final testing based on specifications of the end-user or customer, or based on use by end-users/customers over some limited period of time.
  • load testing - testing an application under heavy loads, such as testing of a web site under a range of loads to determine at what point the system's response time degrades or fails.
  • stress testing - term often used interchangeably with 'load' and 'performance' testing. Also used to describe such tests as system functional testing while under unusually heavy loads, heavy repetition of certain actions or inputs, input of large numerical values, large complex queries to a database system, etc.
  • performance testing - term often used interchangeably with 'stress' and 'load' testing. Ideally 'performance' testing (and any other 'type' of testing) is defined in requirements documentation or QA or Test Plans.
  • usability testing - testing for 'user-friendliness'. Clearly this is subjective, and will depend on the targeted end-user or customer. User interviews, surveys, video recording of user sessions, and other techniques can be used. Programmers and testers are usually not appropriate as usability testers.
  • install/uninstall testing - testing of full, partial, or upgrade install/uninstall processes.
  • recovery testing - testing how well a system recovers from crashes, hardware failures, or other catastrophic problems.
  • failover testing - typically used interchangeably with 'recovery testing'
  • security testing - testing how well the system protects against unauthorized internal or external access, willful damage, etc; may require sophisticated testing techniques.
  • compatibility testing - testing how well software performs in a particular hardware/software/operating system/network/etc. environment.
  • exploratory testing - often taken to mean a creative, informal software test that is not based on formal test plans or test cases; testers may be learning the software as they test it.
  • ad-hoc testing - similar to exploratory testing, but often taken to mean that the testers have significant understanding of the software before testing it.
  • context-driven testing - testing driven by an understanding of the environment, culture, and intended use of software. For example, the testing approach for life-critical medical equipment software would be completely different than that for a low-cost computer game.
  • user acceptance testing - determining if software is satisfactory to an end-user or customer.
  • comparison testing - comparing software weaknesses and strengths to competing products.
  • alpha testing - testing of an application when development is nearing completion; minor design changes may still be made as a result of such testing. Typically done by end-users or others, not by programmers or testers.
  • beta testing - testing when development and testing are essentially completed and final bugs and problems need to be found before final release. Typically done by end-users or others, not by programmers or testers.
  • mutation testing - a method for determining if a set of test data or test cases is useful, by deliberately introducing various code changes ('bugs') and retesting with the original test data/cases to determine if the 'bugs' are detected. Proper implementation requires large computational resources.
(See the Bookstore section's 'Software Testing' category for useful books on Software Testing.)

  • poor requirements - if requirements are unclear, incomplete, too general, and not testable, there may be problems.
  • unrealistic schedule - if too much work is crammed in too little time, problems are inevitable.
  • inadequate testing - no one will know whether or not the software is any good until customers complain or systems crash.
  • featuritis - requests to add on new features after development goals are agreed on.
  • miscommunication - if developers don't know what's needed or customer's have erroneous expectations, problems can be expected.
In agile projects, problems often occur when the project diverges from agile principles (such as forgetting that 'Business people and developers must work together daily throughout the project.' - see the Manifesto for Agile Software Development.)
(See the Bookstore section's 'Software QA', 'Software Engineering', and 'Project Management' categories for useful books with more information.)

  • solid requirements - clear, complete, detailed, cohesive, attainable, testable requirements that are agreed to by all players. In 'agile'-type environments, continuous close coordination with customers/end-users is necessary to ensure that changing/emerging requirements are understood.
  • realistic schedules - allow adequate time for planning, design, testing, bug fixing, re-testing, changes, and documentation; personnel should be able to complete the project without burning out.
  • adequate testing - start testing early on, re-test after fixes or changes, plan for adequate time for testing and bug-fixing. 'Early' testing could include static code analysis/testing, test-first development, unit testing by developers, built-in testing and diagnostic capabilities, automated post-build testing, etc.
  • stick to initial requirements where feasible - be prepared to defend against excessive changes and additions once development has begun, and be prepared to explain consequences. If changes are necessary, they should be adequately reflected in related schedule changes. If possible, work closely with customers/end-users to manage expectations. In 'agile'-type environments, initial requirements may be expected to change significantly, requiring that true agile processes be in place and followed.
  • communication - require walkthroughs and inspections when appropriate; make extensive use of group communication tools - groupware, wiki's, bug-tracking tools and change management tools, intranet capabilities, etc.; ensure that information/documentation is available and up-to-date - preferably electronic, not paper; promote teamwork and cooperation; use prototypes and/or continuous communication with end-users if possible to clarify expectations.
(See the Bookstore section's 'Software QA', 'Software Engineering', and 'Project Management' categories for useful books with more information.)

What is software 'quality'?
Quality software is reasonably bug-free, delivered on time and within budget, meets requirements and/or expectations, and is maintainable. However, quality is obviously a subjective term. It will depend on who the 'customer' is and their overall influence in the scheme of things. A wide-angle view of the 'customers' of a software development project might include end-users, customer acceptance testers, customer contract officers, customer management, the development organization's management/accountants/testers/salespeople, future software maintenance engineers, stockholders, magazine columnists, etc. Each type of 'customer' will have their own slant on 'quality' - the accounting department might define quality in terms of profits while an end-user might define quality as user-friendly and bug-free. (See the Bookstore section's 'Software QA' category for useful books with more information.)

What is 'good code'?
'Good code' is code that works, is reasonably bug free, and is readable and maintainable. Some organizations have coding 'standards' that all developers are supposed to adhere to, but everyone has different ideas about what's best, or what is too many or too few rules. There are also various theories and metrics, such as McCabe Complexity metrics. It should be kept in mind that excessive use of standards and rules can stifle productivity and creativity. 'Peer reviews', 'buddy checks' pair programming, code analysis tools, etc. can be used to check for problems and enforce standards.
For example, in C/C++ coding, here are some typical ideas to consider in setting rules/standards; these may or may not apply to a particular situation:
  • minimize or eliminate use of global variables.
  • use descriptive function and method names - use both upper and lower case, avoid abbreviations, use as many characters as necessary to be adequately descriptive (use of more than 20 characters is not out of line); be consistent in naming conventions.
  • use descriptive variable names - use both upper and lower case, avoid abbreviations, use as many characters as necessary to be adequately descriptive (use of more than 20 characters is not out of line); be consistent in naming conventions.
  • function and method sizes should be minimized; less than 100 lines of code is good, less than 50 lines is preferable.
  • function descriptions should be clearly spelled out in comments preceding a function's code.
  • organize code for readability.
  • use whitespace generously - vertically and horizontally
  • each line of code should contain 70 characters max.
  • one code statement per line.
  • coding style should be consistent throughout a program (eg, use of brackets, indentations, naming conventions, etc.)
  • in adding comments, err on the side of too many rather than too few comments; a common rule of thumb is that there should be at least as many lines of comments (including header blocks) as lines of code.
  • no matter how small, an application should include documentation of the overall program function and flow (even a few paragraphs is better than nothing); or if possible a separate flow chart and detailed program documentation.
  • make extensive use of error handling procedures and status and error logging.
  • for C++, to minimize complexity and increase maintainability, avoid too many levels of inheritance in class hierarchies (relative to the size and complexity of the application). Minimize use of multiple inheritance, and minimize use of operator overloading (note that the Java programming language eliminates multiple inheritance and operator overloading.)
  • for C++, keep class methods small, less than 50 lines of code per method is preferable.
  • for C++, make liberal use of exception handlers

What is 'good design'?
'Design' could refer to many things, but often refers to 'functional design' or 'internal design'. Good internal design is indicated by software code whose overall structure is clear, understandable, easily modifiable, and maintainable; is robust with sufficient error-handling and status logging capability; and works correctly when implemented. Good functional design is indicated by an application whose functionality can be traced back to customer and end-user requirements. (See further discussion of functional and internal design in 'What's the big deal about requirements?' in FAQ #2.) For programs that have a user interface, it's often a good idea to assume that the end user will have little computer knowledge and may not read a user manual or even the on-line help; some common rules-of-thumb include:
  • the program should act in a way that least surprises the user
  • it should always be evident to the user what can be done next and how to exit
  • the program shouldn't let the users do something stupid without warning them.

  • SEI = 'Software Engineering Institute' at Carnegie-Mellon University; initiated by the U.S. Defense Department to help improve software development processes.
  • CMM = 'Capability Maturity Model', now called the CMMI ('Capability Maturity Model Integration'), developed by the SEI. It's a model of 5 levels of process 'maturity' that determine effectiveness in delivering quality software. It is geared to large organizations such as large U.S. Defense Department contractors. However, many of the QA processes involved are appropriate to any organization, and if reasonably applied can be helpful. Organizations can receive CMMI ratings by undergoing assessments by qualified auditors.
Level 1 - characterized by chaos, periodic panics, and heroic
                 efforts required by individuals to successfully
                 complete projects.  Few if any processes in place;
                 successes may not be repeatable.

       Level 2 - software project tracking, requirements management,
                 realistic planning, and configuration management
                 processes are in place; successful practices can
                 be repeated.

       Level 3 - standard software development and maintenance processes
                 are integrated throughout an organization; a Software
                 Engineering Process Group is in place to oversee
                 software processes, and training programs are used to
                 ensure understanding and compliance.

       Level 4 - metrics are used to track productivity, processes,
                 and products.  Project performance is predictable,
                 and quality is consistently high.

       Level 5 - the focus is on continuous process improvement. The
                 impact of new processes and technologies can be
                 predicted and effectively implemented when required.

      Perspective on CMM ratings:  During 1997-2001, 1018 organizations
      were assessed.  Of those, 27% were rated at Level 1, 39% at 2,
      23% at 3, 6% at 4, and  5% at 5.  (For ratings during the period 
      1992-96, 62% were at Level 1, 23% at 2, 13% at 3, 2% at 4, and 
      0.4% at 5.)  The median size of organizations was 100 software 
      engineering/maintenance personnel; 32% of organizations were 
      U.S. federal contractors or agencies.  For those rated at 
      Level 1, the most problematical key process area was in 
      Software Quality Assurance.

  • ISO = 'International Organisation for Standardization' - The ISO 9001:2008 standard (which provides some clarifications of the previous standard 9001:2000) concerns quality systems that are assessed by outside auditors, and it applies to many kinds of production and manufacturing organizations, not just software. It covers documentation, design, development, production, testing, installation, servicing, and other processes. The full set of standards consists of: (a)Q9001-2008 - Quality Management Systems: Requirements; (b)Q9000-2005 - Quality Management Systems: Fundamentals and Vocabulary; (c)Q9004-2009 - Quality Management Systems: Guidelines for Performance Improvements. To be ISO 9001 certified, a third-party auditor assesses an organization, and certification is typically good for about 3 years, after which a complete reassessment is required. Note that ISO certification does not necessarily indicate quality products - it indicates only that documented processes are followed. There are also other software-related ISO standards such as ISO/IEC 25010:2011 which includes a 'quality in use model' composed of five characteristics and a 'product quality model' that covers eight main characteristics of software. Also see for the latest information. In the U.S. the standards can be purchased via the ASQ web site at
    ISO 9126 is a standard for the evaluation of software quality and defines six high level quality characteristics that can be used in software evaluation. It includes functionality, reliability, usability, efficiency, maintainability, and portability.
  • IEEE = 'Institute of Electrical and Electronics Engineers' - among other things, creates standards such as 'IEEE Standard for Software Test Documentation' (IEEE/ANSI Standard 829), 'IEEE Standard of Software Unit Testing (IEEE/ANSI Standard 1008), 'IEEE Standard for Software Quality Assurance Plans' (IEEE/ANSI Standard 730), and others.
  • ANSI = 'American National Standards Institute', the primary industrial standards body in the U.S.; publishes some software-related standards in conjunction with the IEEE and ASQ (American Society for Quality).
  • Other software development/IT management process assessment methods besides CMMI and ISO 9000 include SPICE, Trillium, TickIT, Bootstrap, ITIL, MOF, and CobiT.
  • See the 'Other Resources' section for further information available on the web.

What is the 'software life cycle'?
The life cycle begins when an application is first conceived and ends when it is no longer in use. It includes aspects such as initial concept, requirements analysis, functional design, internal design, documentation planning, test planning, coding, document preparation, integration, testing, maintenance, updates, retesting, phase-out, and other aspects. (See the Bookstore section's 'Software QA', 'Software Engineering', and 'Project Management' categories for useful books with more information.)

What makes a good Software Test engineer?
A good test engineer has a 'test to break' attitude, an ability to take the point of view of the customer, a strong desire for quality, and an attention to detail. Tact and diplomacy are useful in maintaining a cooperative relationship with developers, and an ability to communicate with both technical (developers) and non-technical (customers, management) people is useful. Previous software development experience can be helpful as it provides a deeper understanding of the software development process, gives the tester an appreciation for the developers' point of view, and reduce the learning curve in automated test tool programming. Judgement skills are needed to assess high-risk or critical areas of an application on which to focus testing efforts when time is limited.

What makes a good Software QA engineer?
The same qualities a good tester has are useful for a QA engineer. Additionally, they must be able to understand the entire software development process and how it can fit into the business approach and goals of the organization. Communication skills and the ability to understand various sides of issues are important. In organizations in the early stages of implementing QA processes, patience and diplomacy are especially needed. An ability to find problems as well as to see 'what's missing' is important for inspections and reviews.

What makes a good QA or Test manager?
A good QA, test, or QA/Test(combined) manager should:
  • be familiar with the software development process
  • be able to maintain enthusiasm of their team and promote a positive atmosphere, despite what is a somewhat 'negative' process (e.g., looking for or preventing problems)
  • be able to promote teamwork to increase productivity
  • be able to promote cooperation between software, test, and QA engineers
  • have the diplomatic skills needed to promote improvements in QA processes
  • have the ability to withstand pressures and say 'no' to other managers when quality is insufficient or QA processes are not being adhered to
  • have people judgement skills for hiring and keeping skilled personnel
  • be able to communicate with technical and non-technical people, engineers, managers, and customers.
  • be able to run meetings and keep them focused

What's the role of documentation in QA?
Generally, the larger the team/organization, the more useful it will be to stress documentation, in order to manage and communicate more efficiently. (Note that documentation may be electronic, not necessarily in printable form, and may be embedded in code comments, may be embodied in well-written test cases, user stories, etc.) QA practices may be documented to enhance their repeatability. Specifications, designs, business rules, configurations, code changes, test plans, test cases, bug reports, user manuals, etc. may be documented in some form. There would ideally be a system for easily finding and obtaining information and determining what documentation will have a particular piece of information. Change management for documentation can be used where appropriate. For agile software projects, it should be kept in mind that one of the agile values is "Working software over comprehensive documentation", which does not mean 'no' documentation. Agile projects tend to stress the short term view of project needs; documentation often becomes more important in a project's long-term context.

What's the big deal about 'requirements'?
Depending on the project, it may or may not be a 'big deal'. For agile projects, requirements are expected to change and evolve, and detailed documented requirements may not be needed. However some requirements, in the form of user stories or something similar, are useful. For non-agile types of projects detailed documented requirements are usually needed. (Note that requirements documentation can be electronic, not necessarily in the form of printable documents, and may be embedded in code comments, or may be embodied in well-written test cases, wiki's, user stories, etc.) Requirements are the details describing an application's externally-perceived functionality and properties. Requirements are ideally clear, complete, reasonably detailed, cohesive, attainable, and testable. A non-testable requirement would be, for example, 'user-friendly' (too subjective). A more testable requirement would be something like 'the user must enter their previously-assigned password to access the application'. Determining and organizing requirements details in a useful and efficient way can be a difficult effort; different methods and software tools are available depending on the particular project. Many books are available that describe various approaches to this task. (See the Bookstore section's 'Software Requirements Engineering' category for books on Software Requirements.)
Care should be taken to involve ALL of a project's significant 'customers' in the requirements process. 'Customers' could be in-house personnel or outside personnel, and could include end-users, customer acceptance testers, customer contract officers, customer management, future software maintenance engineers, salespeople, etc. Anyone who could later derail the success of the project if their expectations aren't met should be included if possible.
Organizations vary considerably in their handling of requirements specifications. Often the requirements are spelled out in a document with statements such as 'The product shall.....'. 'Design' specifications should not be confused with 'requirements'; design specifications are ideally traceable back to the requirements.
In some organizations requirements may end up in high level project plans, functional specification documents, in design documents, or in other documents at various levels of detail. No matter what they are called, some type of documentation with detailed requirements will be useful to testers in order to properly plan and execute tests. Without such documentation, there will be no clear-cut way to determine if a software application is performing correctly.
If testable requirements are not available or are only partially available, useful testing can still be performed. In this situation test results may be more oriented to providing information about the state of the software and risk levels, rather than providing pass/fail results. A relevant testing approach in this situation may include an approach called 'exploratory testing'. Many software projects have a mix of documented testable requirements, poorly documented requirements, undocumented requirements, and changing requirements. In such projects a mix of scripted and exploratory testing approaches may be useful. See the 'Other Resources' page in the 'General Software QA and Testing Resources' section for articles on exploratory testing, and in the 'Agile and XP Testing Resources' section for articles on agile software development and testing.)
'Agile' approaches use methods requiring close interaction and cooperation between programmers and stakeholders/customers/end-users to iteratively develop requirements, user stories, etc. In the XP 'test first' approach developers create automated unit testing code before the application code, and these automated unit tests essentially embody the requirements.

What steps are needed to develop and run software tests?
The following are some of the steps to consider:
  • Obtain requirements, functional design, and internal design specifications, user stories, and other available/necessary information
  • Obtain budget and schedule requirements
  • Determine project-related personnel and their responsibilities, reporting requirements, required standards and processes (such as release processes, change processes, etc.)
  • Determine project context, relative to the existing quality culture of the product/organization/business, and how it might impact testing scope, approaches, and methods.
  • Identify application's higher-risk and more important aspects, set priorities, and determine scope and limitations of tests.
  • Determine test approaches and methods - unit, integration, functional, system, security, load, usability tests, etc.
  • Determine test environment requirements (hardware, software, configuration, versions, communications, etc.)
  • Determine testware requirements (automation tools, coverage analyzers, test tracking, problem/bug tracking, etc.)
  • Determine test input data requirements
  • Identify tasks, those responsible for tasks, and labor requirements
  • Set schedule estimates, timelines, milestones
  • Determine, where appropriate, input equivalence classes, boundary value analyses, error classes
  • Prepare test plan document(s) and have needed reviews/approvals
  • Write test cases
  • Have needed reviews/inspections/approvals of test cases
  • Prepare test environment and testware, obtain needed user manuals/reference documents/configuration guides/installation guides, set up test tracking processes, set up logging and archiving processes, set up or obtain test input data
  • Obtain and install software releases
  • Perform tests
  • Evaluate and report results
  • Track problems/bugs and fixes
  • Retest as needed
  • Maintain and update test plans, test cases, test environment, and testware through life cycle

What's a 'test plan'?
A software project test plan is a document that describes the objectives, scope, approach, and focus of a software testing effort. The process of preparing a test plan is a useful way to think through the efforts needed to validate the acceptability of a software product. The completed document will help people outside the test group understand the 'why' and 'how' of product validation. It should be thorough enough to be useful but not so overly detailed that no one outside the test group will read it. The following are some of the items that might be included in a test plan, depending on the particular project:
  • Title
  • Identification of software including version/release numbers
  • Revision history of document including authors, dates, approvals
  • Table of Contents
  • Purpose of document, intended audience
  • Objective of testing effort
  • Software product overview
  • Relevant related document list, such as requirements, design documents, other test plans, etc.
  • Relevant standards or legal requirements
  • Traceability requirements
  • Relevant naming conventions and identifier conventions
  • Overall software project organization and personnel/contact-info/responsibilities
  • Test organization and personnel/contact-info/responsibilities
  • Assumptions and dependencies
  • Project risk analysis
  • Testing priorities and focus
  • Scope and limitations of testing
  • Test outline - a decomposition of the test approach by test type, feature, functionality, process, system, module, etc. as applicable
  • Outline of data input equivalence classes, boundary value analysis, error classes
  • Test environment - hardware, operating systems, other required software, data configurations, interfaces to other systems
  • Test environment validity analysis - differences between the test and production systems and their impact on test validity.
  • Test environment setup and configuration issues
  • Software migration processes
  • Software CM processes
  • Test data setup requirements
  • Database setup requirements
  • Outline of system-logging/error-logging/other capabilities, and tools such as screen capture software, that will be used to help describe and report bugs
  • Discussion of any specialized software or hardware tools that will be used by testers to help track the cause or source of bugs
  • Test automation - justification and overview
  • Test tools to be used, including versions, patches, etc.
  • Test script/test code maintenance processes and version control
  • Problem tracking and resolution - tools and processes
  • Project test metrics to be used
  • Reporting requirements and testing deliverables
  • Software entrance and exit criteria
  • Initial sanity testing period and criteria
  • Test suspension and restart criteria
  • Personnel allocation
  • Personnel pre-training needs
  • Test site/location
  • Outside test organizations to be utilized and their purpose, responsibilties, deliverables, contact persons, and coordination issues
  • Relevant proprietary, classified, security, and licensing issues.
  • Open issues
  • Appendix - glossary, acronyms, etc.
(See the Bookstore section's 'Software Testing' and 'Software QA' categories for useful books with more information.)

What's a 'test case'?
A test case describes an input, action, or event and an expected response, to determine if a feature of a software application is working correctly. A test case may contain particulars such as test case identifier, test case name, objective, test conditions/setup, input data requirements, steps, and expected results. The level of detail may vary significantly depending on the organization and project context.
Note that the process of developing test cases can help find problems in the requirements or design of an application, since it requires completely thinking through the operation of the application. For this reason, it's useful to prepare test cases early in the development cycle if possible.

What should be done after a bug is found?
The bug needs to be communicated and assigned to developers that can fix it. After the problem is resolved, fixes should be re-tested, and determinations made regarding requirements for regression testing to check that fixes didn't create problems elsewhere. If a problem-tracking system is in place, it should encapsulate these processes. A variety of commercial problem-tracking/management software tools are available (see the 'Tools' section for web resources with listings of such tools). The following are items to consider in the tracking process:
  • Complete information such that developers can understand the bug, get an idea of it's severity, and reproduce it if necessary.
  • Bug identifier (number, ID, etc.)
  • Current bug status (e.g., 'Released for Retest', 'New', etc.)
  • The application name or identifier and version
  • The function, module, feature, object, screen, etc. where the bug occurred
  • Environment specifics, system, platform, relevant hardware specifics
  • Test case name/number/identifier
  • One-line bug description
  • Full bug description
  • Description of steps needed to reproduce the bug if not covered by a test case or if the developer doesn't have easy access to the test case/test script/test tool
  • Names and/or descriptions of file/data/messages/etc. used in test
  • File excerpts/error messages/log file excerpts/screen shots/test tool logs that would be helpful in finding the cause of the problem
  • Severity estimate (a 5-level range such as 1-5 or 'critical'-to-'low' is common)
  • Was the bug reproducible?
  • Tester name
  • Test date
  • Bug reporting date
  • Name of developer/group/organization the problem is assigned to
  • Description of problem cause
  • Description of fix
  • Code section/file/module/class/method that was fixed
  • Date of fix
  • Application version that contains the fix
  • Tester responsible for retest
  • Retest date
  • Retest results
  • Regression testing requirements
  • Tester responsible for regression tests
  • Regression testing results
A reporting or tracking process should enable notification of appropriate personnel at various stages. For instance, testers need to know when retesting is needed, developers need to know when bugs are found and how to get the needed information, and reporting/summary capabilities are needed for managers.

What is 'configuration management'?
Configuration management covers the processes used to control, coordinate, and track: code, requirements, documentation, problems, change requests, designs, tools/compilers/libraries/patches, changes made to them, and who makes the changes. (See the 'Tools' section for web resources with listings of configuration management tools. Also see the Bookstore section's 'Configuration Management' category for useful books with more information.)

What if the software is so buggy it can't really be tested at all?
The best bet in this situation is for the testers to go through the process of reporting whatever bugs or blocking-type problems initially show up, with the focus being on critical bugs. Since this type of problem can severely affect schedules, and indicates deeper problems in the software development process (such as insufficient unit testing or insufficient integration testing, poor design, improper build or release procedures, etc.) managers should be notified, and provided with some documentation as evidence of the problem.

How can it be known when to stop testing?
This can be difficult to determine. Most modern software applications are so complex, and run in such an interdependent environment, that complete testing can never be done. Common factors in deciding when to stop are:
  • Deadlines (release deadlines, testing deadlines, etc.)
  • Test cases completed with certain percentage passed
  • Test budget depleted
  • Coverage of code/functionality/requirements reaches a specified point
  • Bug rate falls below a certain level
  • Beta or alpha testing period ends
Also see 'Who should decide when software is ready to be released?' in the LFAQ section.

What if there isn't enough time for thorough testing?
Use risk analysis, along with discussion with project stakeholders, to determine where testing should be focused.
Since it's rarely possible to test every possible aspect of an application, every possible combination of events, every dependency, or everything that could go wrong, risk analysis is appropriate to most software development projects. This requires judgement skills, common sense, and experience. (If warranted, formal methods are also available.) Considerations can include:
  • Which functionality is most important to the project's intended purpose?
  • Which functionality is most visible to the user?
  • Which functionality has the largest safety impact?
  • Which functionality has the largest financial impact on users?
  • Which aspects of the application are most important to the customer?
  • Which aspects of the application can be tested early in the development cycle?
  • Which parts of the code are most complex, and thus most subject to errors?
  • Which parts of the application were developed in rush or panic mode?
  • Which aspects of similar/related previous projects caused problems?
  • Which aspects of similar/related previous projects had large maintenance expenses?
  • Which parts of the requirements and design are unclear or poorly thought out?
  • What do the developers think are the highest-risk aspects of the application?
  • What kinds of problems would cause the worst publicity?
  • What kinds of problems would cause the most customer service complaints?
  • What kinds of tests could easily cover multiple functionalities?
  • Which tests will have the best high-risk-coverage to time-required ratio?

What if the project isn't big enough to justify extensive testing?
Consider the impact of project errors, not the size of the project. However, if extensive testing is still not justified, risk analysis is again needed and the same considerations as described previously in 'What if there isn't enough time for thorough testing?' apply. The tester might then do ad hoc or exploratory testing, or write up a limited test plan based on the risk analysis.

How does a client/server environment affect testing?
Client/server applications can be highly complex due to the multiple dependencies among clients, data communications, hardware, and servers, especially in multi-tier systems. Thus testing requirements can be extensive. When time is limited (as it usually is) the focus should be on integration and system testing. Additionally, load/stress/performance testing may be useful in determining client/server application limitations and capabilities. There are commercial and open source tools to assist with such testing. (See the 'Tools' section for web resources with listings that include these kinds of test tools.)

How can World Wide Web sites be tested?
Web sites are essentially client/server applications - with web servers and 'browser' clients. Consideration should be given to the interactions between html pages, web services, encrypted communications, Internet connections, firewalls, applications that run in web pages (such as javascript, flash, other plug-in applications), the wide variety of applications that could run on the server side, etc. Additionally, there are a wide variety of servers and browsers, mobile platforms, various versions of each, small but sometimes significant differences between them, variations in connection speeds, rapidly changing technologies, and multiple standards and protocols. The end result is that testing for web sites can become a major ongoing effort. Other considerations might include:
  • What are the expected loads on the server, and what kind of performance is required under such loads (such as web server response time, database query response times). What kinds of tools will be needed for performance testing (such as web load testing tools, other tools already in house that can be adapted, load generation appliances, etc.)?
  • Who is the target audience? What kind and version of browsers will they be using, and how extensively should testing be for these variations? What kind of connection speeds will they by using? Are they intra- organization (thus with likely high connection speeds and similar browsers) or Internet-wide (thus with a wider variety of connection speeds and browser types)?
  • What kind of performance is expected on the client side (e.g., how fast should pages appear, how fast should flash, applets, etc. load and run)?
  • Will down time for server and content maintenance/upgrades be allowed? how much?
  • What kinds of security (firewalls, encryption, passwords, functionality, etc.) will be required and what is it expected to do? How can it be tested?
  • What internationalization/localization/language requirements are there, and how are they to be verified?
  • How reliable are the site's Internet connections required to be? And how does that affect backup system or redundant connection requirements and testing?
  • What processes will be required to manage updates to the web site's content, and what are the requirements for maintaining, tracking, and controlling page content, graphics, links, etc.?
  • Which HTML and related specification will be adhered to? How strictly? What variations will be allowed for targeted browsers?
  • Will there be any standards or requirements for page appearance and/or graphics, 508 compliance, etc. throughout a site or parts of a site?
  • Will there be any development practices/standards utilized for web page components and identifiers, which can significantly impact test automation.
  • How will internal and external links be validated and updated? how often?
  • Can testing be done on the production system, or will a separate test system be required? How are browser caching, variations in browser option settings, connection variabilities, and real-world internet 'traffic congestion' problems to be accounted for in testing?
  • How extensive or customized are the server logging and reporting requirements; are they considered an integral part of the system and do they require testing?
  • How are flash, applets, javascripts, ActiveX components, etc. to be maintained, tracked, controlled, and tested?
Some sources of web site security information include the Usenet newsgroup '' and links concerning web site security in the 'Other Resources' section. Hundreds of web site test tools are available and more than 550 of them are listed in the 'Web Test Tools' section.

How is testing affected by object-oriented designs?
Well-engineered object-oriented design can make it easier to trace from code to internal design to functional design to requirements. While there will be little affect on black box testing (where an understanding of the internal design of the application is unnecessary), white-box testing can be oriented to the application's objects, methods, etc. If the application was well-designed this can simplify test design and test automation design.

What is Extreme Programming and what's it got to do with testing?
Extreme Programming (XP) is a software development approach for small teams on risk-prone projects with unstable requirements. It was created by Kent Beck who described the approach in his book 'Extreme Programming Explained' (See the Books page.). Testing ('extreme testing') is a core aspect of Extreme Programming. Programmers are expected to write unit and functional test code first - before writing the application code. Test code is under source control along with the rest of the code. Customers are expected to be an integral part of the project team and to help develope scenarios for acceptance/black box testing. Acceptance tests are preferably automated, and are modified and rerun for each of the frequent development iterations. QA and test personnel are also required to be an integral part of the project team. Detailed requirements documentation is not used, and frequent re-scheduling, re-estimating, and re-prioritizing is expected. For more info on XP and other 'agile' software development approaches (Scrum, Crystal, etc.) see the resource listings in the 'Agile and XP Testing Resources' section.

1 comment:

  1. Astonishing!, I was looking for a brief description about the main activities related to QA, and I found your post, thanks for your effort.

    Best Regards.