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Software testing is the process used to assess the quality of computer software. In the context of Software engineering, software quality measures how well Software is designed ( quality of design) and how well the software conforms Software testing is an empirical technical investigation conducted to provide stakeholders with information about the quality of the product or service under test[1] , with respect to the context in which it is intended to operate. This includes, but is not limited to, the process of executing a program or application with the intent of finding software bugs. A software bug (or just “bug” is an error flaw mistake Failure, fault or “undocumented feature” in a Computer program that prevents it Quality is not an absolute; it is value to some person. With that in mind, testing can never completely establish the correctness of arbitrary computer software; testing furnishes a criticism or comparison that compares the state and behaviour of the product against a specification. An important point is that software testing should be distinguished from the separate discipline of Software Quality Assurance (S. Software quality assurance ( SQA) consists of a means of monitoring the Software engineering processes and methods used to ensure quality Q. A. ), which encompasses all business process areas, not just testing.

Over its existence, computer software has continued to grow in complexity and size. Every software product has a target audience. For example, a video game software has its audience completely different from banking software. Therefore, when an organization develops or otherwise invests in a software product, it presumably must assess whether the software product will be acceptable to its end users, its target audience, its purchasers, and other stakeholders. Software testing is the process of attempting to make this assessment.

A study conducted by NIST in 2002 reports that software bugs cost the U. S. economy $59. 5 billion annually. More than a third of this cost could be avoided if better software testing was performed. [2]

Software development process
Activities and steps
Requirements · Architecture
Design · Implementation
Testing · Deployment
Models
Agile · Cleanroom · Iterative · RAD
RUP · Spiral · Waterfall · XP · Scrum
Supporting disciplines
Configuration management
Documentation
Quality assurance (SQA)
Project management
User experience design
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Contents

Scope

Software testing may be viewed as an important part of the software quality assurance (SQA) process. A software development process is a structure imposed on the development of a software product Requirements analysis in Systems engineering and Software engineering, encompasses those tasks that go into determining the needs or conditions to meet for a new or The software architecture of a program or computing system is the structure or structures of the system, which comprise software components the externally visible properties Software design is a process of problem-solving and planning for a Software solution Software deployment is all of the activities that make a Software system available for use Agile software development refers to a group of Software development methodologies that are based on similar principles The Cleanroom Software Engineering process is a Software development process intended to produce software with a certifiable level of Reliability. Iterative and Incremental development is a cyclic Software development process developed in response to the weaknesses of the Waterfall model. Rapid application development ( RAD) is a Software development process, which involves iterative development and the construction of Prototypes The Rational Unified Process ( RUP) is an Iterative Software development process framework created by the Rational Software Corporation a division The spiral model is a Software development process combining elements of both Design and Prototyping -in-stages in an effort to combine advantages of The waterfall model is a sequential Software development process (a process for the creation of software in which development is seen as flowing steadily downwards Extreme Programming (or XP) is a Software engineering methodology (and a form of Agile software development) Proponents of Extreme Programming and agile Scrum is an iterative incremental process of software development commonly used with Agile software development. In Software engineering, software configuration Software documentation or source code documentation is written text that accompanies Computer Software. Software quality assurance ( SQA) consists of a means of monitoring the Software engineering processes and methods used to ensure quality Project Management is the discipline of planning organizing and managing resources to bring about the successful completion of specific project goals and objectives User experience design is a subset of the field of Experience design which pertains to the creation of the architecture and interaction models which impact a user's perception Software quality assurance ( SQA) consists of a means of monitoring the Software engineering processes and methods used to ensure quality In SQA, software process specialists and auditors take a broader view on software and its development. They examine and change the software engineering process itself to reduce the amount of faults that end up in defect rate. What constitutes an acceptable defect rate depends on the nature of the software. An arcade video game designed to simulate flying an airplane would presumably have a much higher tolerance for defects than software used to control an actual airliner. Although there are close links with SQA testing departments often exist independently, and there may be no SQA areas in some companies.

The software faults occur through the following process. A programmer makes an error (mistake), which results in a defect (fault, bug) in the software source code. In document ISO/CD 10303-226, a fault is defined as an abnormal condition or defect at the component equipment or sub-system level which may lead to a Failure. In Computer science, source code (commonly just source or code) is any sequence of statements or declarations written in some Human-readable If this defect is executed, in certain situations the system will produce wrong results, causing a failure. Failure ( fail, phail or flop) in general refers to the state or Condition of not meeting a desirable or intended objective [3] Not all defects will necessarily result in failures. For example, defects in dead code will never result in failures. In Computer programming, unreachable code, or dead code, is code that exists in the Source code of a program but can never be executed A defect can turn into a failure when the environment is changed. Examples of these changes in environment include the software being run on a new hardware platform, alterations in source data or interacting with different software. Hardware is a general term that refers to the physical artifacts of a Technology. Source data is the origin of Information found in Electronic media. [3]

A problem with software testing is that testing all combinations of inputs and preconditions is not feasible when testing anything other than a simple product. [4] This means that the number of defects in a software product can be very large and defects that occur infrequently are difficult to find in testing. A software bug (or just “bug” is an error flaw mistake Failure, fault or “undocumented feature” in a Computer program that prevents it More significantly, parafunctional dimensions of quality--for example, usability, scalability, performance, compatibility, reliability--can be highly subjective; something that constitutes sufficient value to one person may be intolerable to another.

There are many approaches to software testing. Reviews, walkthroughs or inspections are considered as static testing, whereas actually running the program with a given set of test cases in a given development stage is referred to as dynamic testing. Static testing is a form of software testing where the software isn't actually used Dynamic testing (or dynamic analysis is a term used in Software engineering to describe the testing of the dynamic behavior of code

Software testing is used in association with verification and validation:[5]

Software testing can be done by software testers. Until the 1950s the term software tester was used generally, but later it was also seen as a separate profession. Regarding the periods and the different goals in software testing[6] there have been established different roles: test lead/manager, test designer, tester, test automater/automation developer, and test administrator.

History

The separation of debugging from testing was initially introduced by Glenford J. Myers in 1979. [7] Although his attention was on breakage testing, it illustrated the desire of the software engineering community to separate fundamental development activities, such as debugging, from that of verification. Dr. Dave Gelperin and Dr. Doctor Dave Gelperin was the chair of the IEEE 829 -1989 (Test Documentation Standard William C. Hetzel classified in 1988 the phases and goals in software testing in the following stages:[8]

Testing methods

Software testing methods are traditionally divided into black box testing and white box testing. Doctor William C Hetzel wrote the book The Complete Guide to Software Testing it continues to be pivotal in the Software testing culture and remains a consistent Black box testing takes an external perspective of the test object to derive test cases Compare with Black box testing. White box testing (aka clear box testing glass box testing or structural testing uses an internal perspective These two approaches are used to describe the point of view that a test engineer takes when designing test cases.

Black box testing treats the software as a black-box without any understanding of internal behavior. It aims to test the functionality according to the requirements. [14] Thus, the tester inputs data and only sees the output from the test object. This level of testing usually requires thorough test cases to be provided to the tester who then can simply verify that for a given input, the output value (or behavior), is the same as the expected value specified in the test case. Black box testing methods include: equivalence partitioning, boundary value analysis, all-pairs testing, fuzz testing, model-based testing, traceability matrix etc. Equivalence partitioning is a Software testing related technique with the goal To reduce the number of test cases to a necessary minimum Boundary value analysis is a Software testing design technique used to determine test cases covering Off-by-one errors Introduction Testing experience All-pairs testing or pairwise testing is a Combinatorial Software testing method that for each pair of input parameters to a system (typically a Fuzz testing or fuzzing is a Software testing technique that provides random data ("fuzz" to the inputs of a program. Model-based testing is Software testing in which Test cases are derived in whole or in part from a model that describes some (usually functional aspects A traceability matrix is a table that correlates any two baselined documents that require a many to many relationship to determine the completeness of the relationship

White box testing, however, is when the tester has access to the internal data structures, code, and algorithms. White box testing methods include creating tests to satisfy some code coverage criteria. Code coverage is a measure used in Software testing. It describes the degree to which the Source code of a program has been tested For example, the test designer can create tests to cause all statements in the program to be executed at least once. Other examples of white box testing are mutation testing and fault injection methods. Mutation testing (sometimes also called mutation analysis) is a method of Software testing, which involves modifyingprogram's Source code in small ways In Software testing, fault injection is a technique for improving the coverage of a test by introducing faults in order to test code paths in particular Error White box testing includes all static testing.

White box testing methods can also be used to evaluate the completeness of a test suite that was created with black box testing methods. This allows the software team to examine parts of a system that are rarely tested and ensures that the most important function points have been tested. A function point is a unit of measurement to express the amount of business functionality an information system provides to a user [15] Two common forms of code coverage are function coverage, which reports on functions executed and statement coverage, which reports on the number of lines executed to complete the test. They both return a coverage metric, measured as a percentage.

In recent years the term grey box testing has come into common usage. This involves having access to internal data structures and algorithms for purposes of designing the test cases, but testing at the user, or black-box level. Manipulating input data and formatting output do not qualify as grey-box because the input and output are clearly outside of the black-box we are calling the software under test. This is particularly important when conducting integration testing between two modules of code written by two different developers, where only the interfaces are exposed for test. 'Integration testing'(sometimes called Integration and Testing abbreviated I&T) is the phase of Software testing in which individual software modules are combined and tested Grey box testing may also include reverse engineering to determine, for instance, boundary values. Reverse engineering (RE is the process of discovering the technological principles of a device object or system through analysis of its structure function and operation

Special methods exist to test non-functional aspects of software. Performance testing checks to see if the software can handle large quantities of data or users. In Software engineering, performance testing is testing that is performed from one perspective to determine how fast some aspect of a system performs under a particular Load testing is the process of creating demand on a system or device and measuring its response Usability testing is needed to check if the user interface is easy to use and understand. Usability testing is a technique used to evaluate a product by testing it on users Security testing is essential for software which processes confidential data and to prevent system intrusion by hackers. Security Testing: (The Process to determine that an IS (Information System protects data and maintains functionality as intended A backdoor in a Computer system (or Cryptosystem or Algorithm) is a method of bypassing normal Authentication, securing remote access to a computer In common usage hacker is generic term for a computer criminal often with a specific specialty in computer intrusion To test internationalization and localization aspects of software a pseudolocalization method can be used. In Computing, Internationalization and localization (also spelled internationalisation and localisation, see spelling differences) are means of adapting Pseudolocalization is a Software testing method that is used to test internationalization aspects of software

Testing process

A common practice of software testing is performed by an independent group of testers after the functionality is developed before it is shipped to the customer. [16] This practice often results in the testing phase being used as project buffer to compensate for project delays, thereby compromising the time devoted to testing. Project Management is the discipline of planning organizing and managing resources to bring about the successful completion of specific project goals and objectives [17] Another practice is to start software testing at the same moment the project starts and it is a continuous process until the project finishes. [18]

In counterpoint, some emerging software disciplines such as extreme programming and the agile software development movement, adhere to a "test-driven software development" model. Extreme Programming (or XP) is a Software engineering methodology (and a form of Agile software development) Proponents of Extreme Programming and agile Agile software development refers to a group of Software development methodologies that are based on similar principles Test-Driven Development (TDD is a Software development technique consisting of short iterations where new Test cases covering the desired improvement or In this process unit tests are written first, by the software engineers (often with pair programming in the extreme programming methodology). In Computer programming, unit testing is a method of testing that verifies the individual units of Source code are working properly Software engineering is the application of a systematic disciplined quantifiable approach to the development operation and maintenance of Software. Pair programming is a Software development technique in which two programmers work together at one keyboard Of course these tests fail initially; as they are expected to. Then as code is written it passes incrementally larger portions of the test suites. The test suites are continuously updated as new failure conditions and corner cases are discovered, and they are integrated with any regression tests that are developed. Unit tests are maintained along with the rest of the software source code and generally integrated into the build process (with inherently interactive tests being relegated to a partially manual build acceptance process).

Testing can be done on the following levels:

Before shipping the final version of software, alpha and beta testing are often done additionally:

Finally, acceptance testing can be conducted by the end-user, customer, or client to validate whether or not to accept the product. In Engineering and its various subdisciplines, acceptance testing is Black-box testing performed on a System (e Acceptance testing may be performed as part of the hand-off process between any two phases of development.

Regression testing

Main article: Regression testing

After modifying software, either for a change in functionality or to fix defects, a regression test re-runs previously passing tests on the modified software to ensure that the modifications haven't unintentionally caused a regression of previous functionality. Regression testing is any type of Software testing which seeks to uncover software regressions. Regression testing is any type of Software testing which seeks to uncover software regressions. A software regression is a Software bug which makes a feature stop functioning as intended after a certain event (for example a system upgrade system patching or Regression testing can be performed at any or all of the above test levels. These regression tests are often automated. Test automation is the use of Software to control the execution of tests the comparison of actual outcomes to predicted outcomes the setting up of test preconditions

More specific forms of regression testing are known as sanity testing, when quickly checking for bizarre behaviour, and smoke testing when testing for basic functionality. A sanity test or sanity check is a basic test to quickly evaluate the validity of a claim or calculation Smoke testing is a term used in Plumbing, Woodwind repair Electronics, Computer software development and the Entertainment industry

Finding faults early

It is commonly believed that the earlier a defect is found the cheaper it is to fix it. [22] The following table shows the cost of fixing the defect depending on the stage it was found. [23] For example, if a problem in requirements is found only post-release, then it would cost 10-100 times more to fix it comparing to the cost if the same fault was already found by the requirements review.

Time Introduced Time Detected
Requirements Architecture Construction System Test Post-Release
Requirements 1 3 5-10 10 10-100
Architecture - 1 10 15 25-100
Construction - - 1 10 10-25

Measuring software testing

Usually, quality is constrained to such topics as correctness, completeness, security, but can also include more technical requirements as described under the ISO standard ISO 9126, such as capability, reliability, efficiency, portability, maintainability, compatibility, and usability. In theoretical Computer science, correctness of an Algorithm is asserted when it is said that the algorithm is correct with respect to a specification. A computer security audit is a manual or systematic measurable technical assessment of a system or application ISO 9126 is an International standard for the Evaluation of Software quality. In Computer science, efficiency is used to describe properties of an Algorithm relating to how much of various types of resources it consumes See also Software portability In Computer science, porting is the process of adapting software so that an executable program can be created In Software testing, based on the definition given in ISO 9126, the ease with which a software product can be modified in order to correct defects meet

There are a number of common software measures, often called "metrics", which are used to measure the state of the software or the adequacy of the testing.

Testing artifacts

Software testing process can produce several artifacts. The term artifact in connection with software development is largely associated with specific development methods or processes e A test case is a software testing document, which consists of event, action, input, output, expected result, and actual result. A test case in Software engineering is a set of conditions or variables under which a tester will determine if a Requirement or Use case upon Clinically defined a test case is an input and an expected result. [24] This can be as pragmatic as 'for condition x your derived result is y', whereas other test cases described in more detail the input scenario and what results might be expected. It can occasionally be a series of steps (but often steps are contained in a separate test procedure that can be exercised against multiple test cases, as a matter of economy) but with one expected result or expected outcome. The optional fields are a test case ID, test step or order of execution number, related requirement(s), depth, test category, author, and check boxes for whether the test is automatable and has been automated. Larger test cases may also contain prerequisite states or steps, and descriptions. A test case should also contain a place for the actual result. These steps can be stored in a word processor document, spreadsheet, database, or other common repository. In a database system, you may also be able to see past test results and who generated the results and the system configuration used to generate those results. These past results would usually be stored in a separate table.

The test script is the combination of a test case, test procedure, and test data. A test script in Software Testing is a set of instructions that will be performed on the System Initially the term was derived from the product of work created by automated regression test tools. Today, test scripts can be manual, automated, or a combination of both. A test script in Software Testing is a set of instructions that will be performed on the System

The most common term for a collection of test cases is a test suite. In Software development, a test suite, less commonly known as a validation suite, is a collection of Test cases that are intended to be used to test The test suite often also contains more detailed instructions or goals for each collection of test cases. It definitely contains a section where the tester identifies the system configuration used during testing. A group of test cases may also contain prerequisite states or steps, and descriptions of the following tests.

A test specification is called a test plan. A test plan is a systematic approach to testing a system such as a Machine or Software. The developers are well aware what test plans will be executed and this information is made available to the developers. This makes the developers more cautious when developing their code. This ensures that the developers code is not passed through any surprise test case or test plans.

The software, tools, samples of data input and output, and configurations are all referred to collectively as a test harness. In Software testing, a test harness or automated test framework is a collection of Software and test data configured to test a program unit by running it

A sample testing cycle

Although varies between organizations, there is a cycle to testing:

Controversy

Main article: Software testing controversies

Some of the major controversies include:

Certification

Several certification programs exist to support the professional aspirations of software testers and quality assurance specialists. No certification currently offered actually requires the applicant to demonstrate the ability to test software. No certification is based on a widely accepted body of knowledge. This has led some to declare that the testing field is not ready for certification. [27] Certification itself cannot measure an individual's productivity, their skill, or practical knowledge, and cannot guarantee their competence, or professionalism as a tester. [28]

Certifications can be grouped into: exam-based and education-based. Exam-based certifications: For these there is the need to pass an exam, which can also be learned by self-study: e. g. for ISTQB or QAI. Education-based certifications are instructor-led sessions, where each course has to be passed, e. g. IIST (International Institute for Software Testing).

Testing certifications

Quality assurance certifications

See also

References

  1. ^ Exploratory Testing, Cem Kaner, Florida Institute of Technology, Quality Assurance Institute Worldwide Annual Software Testing Conference, Orlando, FL, November 2006
  2. ^ Software errors cost U.S. economy $59.5 billion annually, NIST report
  3. ^ a b Section 1. ISEB ( Information Systems Examinations Board) is a worldwide exam body and a part of the British Computer Society. The ISTQB ( International Software Testing Qualifications Board) was founded in Edinburgh in November 2002 The ISTQB ( International Software Testing Qualifications Board) was founded in Edinburgh in November 2002 American Society for Quality (ASQ, formerly known as American Society for Quality Control (ASQC, is a knowledge-based global community of Quality control experts Quality Assurance International (QAI is a US -based international Organic certification company that is authorized by the United States Department of Agriculture Dynamic program analysis is the analysis of computer software that is performed with executing programs built from that Software on a real or virtual processor (analysis performed In the context of hardware and software systems formal verification is the act of proving or disproving the Correctness of intended Algorithms underlying Reverse Semantic Traceability ( RST) is a Quality control method for verification improvement that helps to insure high quality of artifacts by backward translation Static code analysis is the analysis of computer Software that is performed without actually executing programs built from that software (analysis performed on executing In Computer science, GUI software testing is the process of testing a product that uses a Graphical user interface, to ensure it meets its written specifications Web testing is the name given to Software testing that focuses on Web applications, and is one of the fastest growing areas of software testing 1. 2, Certified Tester Foundation Level Syllabus, International Software Testing Qualifications Board
  4. ^ Principle 2, Section 1. The ISTQB ( International Software Testing Qualifications Board) was founded in Edinburgh in November 2002 3, Certified Tester Foundation Level Syllabus, International Software Testing Qualifications Board
  5. ^ Tran, Eushiuan (1999). The ISTQB ( International Software Testing Qualifications Board) was founded in Edinburgh in November 2002 "Verification/Validation/Certification", in Koopman, P. : Topics in Dependable Embedded Systems. USA: Carnegie Mellon University. Retrieved on 2008-01-13. 2008 ( MMVIII) is the current year in accordance with the Gregorian calendar, a Leap year that started on Tuesday of the Common Events 532 - Nika riots in Constantinople. 888 - Odo Count of Paris becomes King of the Franks  
  6. ^ see D. Gelperin and W. C. Hetzel
  7. ^ Myers, Glenford J. (1979). The Art of Software Testing. John Wiley and Sons. ISBN 0-471-04328-1.  
  8. ^ Gelperin, D. ; B. Hetzel (1988). "The Growth of Software Testing". CACM 31 (6). ISSN 0001-0782.  
  9. ^ until 1956 it was the debugging oriented period, when testing was often associated to debugging: there was no clear difference between testing and debugging. Gelperin, D. ; B. Hetzel (1988). "The Growth of Software Testing". CACM 31 (6). ISSN 0001-0782.  
  10. ^ From 1957-1978 there was the demonstration oriented period where debugging and testing was distinguished now - in this period it was shown, that software satisfies the requirements. Gelperin, D. ; B. Hetzel (1988). "The Growth of Software Testing". CACM 31 (6). ISSN 0001-0782.  
  11. ^ The time between 1979-1982 is announced as the destruction oriented period, where the goal was to find errors. Gelperin, D. ; B. Hetzel (1988). "The Growth of Software Testing". CACM 31 (6). ISSN 0001-0782.  
  12. ^ 1983-1987 is classified as the evaluation oriented period: intention here is that during the software lifecycle a product evaluation is provided and measuring quality. Gelperin, D. ; B. Hetzel (1988). "The Growth of Software Testing". CACM 31 (6). ISSN 0001-0782.  
  13. ^ From 1988 on it was seen as prevention oriented period where tests were to demonstrate that software satisfies its specification, to detect faults and to prevent faults. Gelperin, D. ; B. Hetzel (1988). "The Growth of Software Testing". CACM 31 (6). ISSN 0001-0782.  
  14. ^ Laycock, G. T. (1993). "The Theory and Practice of Specification Based Software Testing" (PostScript). PostScript ( PS) is a dynamically typed concatenative Programming language created by John Warnock and Charles Geschke in 1982 . Dept of Computer Science, Sheffield University, UK Retrieved on 2008-02-13. 2008 ( MMVIII) is the current year in accordance with the Gregorian calendar, a Leap year that started on Tuesday of the Common Events 1258 - Baghdad falls to the Mongols, and the Abbasid Caliphate is destroyed
  15. ^ Introduction, Code Coverage Analysis, Steve Cornett
  16. ^ e)Testing Phase in Software Testing:-
  17. ^ Myers, Glenford J. (1979). The Art of Software Testing. John Wiley and Sons, 145-146. ISBN 0-471-04328-1.  
  18. ^ Dustin, Elfriede (2002). Effective Software Testing. Addison Wesley, 3. ISBN 0-20179-429-2.  
  19. ^ Binder, Robert V. (1999). Testing Object-Oriented Systems: Objects, Patterns, and Tools. Addison-Wesley Professional, 45. ISBN 0-201-80938-9.  
  20. ^ Beizer, Boris (1990). Software Testing Techniques, Second Edition, pp. 21,430. ISBN 0-442-20672-0.  
  21. ^ IEEE (1990). IEEE Standard Computer Dictionary: A Compilation of IEEE Standard Computer Glossaries. New York: IEEE. ISBN 1559370793.  
  22. ^ Kaner, Cem; James Bach, Bret Pettichord (2001). Cem Kaner JD, PhD, is a Professor of Software Engineering at Florida Institute of Technology, and the Director of Florida Tech's Lessons Learned in Software Testing: A Context-Driven Approach. Wiley, 4. John Wiley & Sons Inc, also referred to as Wiley, is a global Publishing company that markets its products to professionals and consumers students and instructors ISBN 0-471-08112-4.  
  23. ^ McConnell, Steve (2004). Code Complete, 2nd edition, Microsoft Press, 960. ISBN 0-7356-1967-0.  
  24. ^ IEEE (1998). IEEE standard for software test documentation. IEEE 829-1998, also known as the 829 Standard for Software Test Documentation, is an IEEE standard that specifies the form of a set of documents for use in eight defined New York: IEEE. ISBN 0-7381-1443-X.  
  25. ^ context-driven-testing.com
  26. ^ An example is Mark Fewster, Dorothy Graham: Software Test Automation. Addison Wesley, 1999, ISBN 0-201-33140-3
  27. ^ Kaner, Cem (2001). NSF grant proposal to "lay a foundation for significant improvements in the quality of academic and commercial courses in software testing" (pdf).
  28. ^ Kaner, Cem (2003). Measuring the Effectiveness of Software Testers (pdf).
  29. ^ Quality Assurance Institute
  30. ^ International Institute for Software Testing
  31. ^ K. J. Ross & Associates
  32. ^ International Institute for Software Testing
  33. ^ a b ISTQB.
  34. ^ a b ISTQB in the U.S..
  35. ^ ALATS
  36. ^ American Society for Quality
  37. ^ Quality Assurance Institute

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