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Regression Testing
Regression testing (rarely, ''non-regression testing'') is re-running functional and non-functional tests to ensure that previously developed and tested software still performs as expected after a change. If not, that would be called a '' regression''. Changes that may require regression testing include bug fixes, software enhancements, configuration changes, and even substitution of electronic components ( hardware). As regression test suites tend to grow with each found defect, test automation is frequently involved. Sometimes a change impact analysis is performed to determine an appropriate subset of tests (''non-regression analysis''). Background As software is updated or changed, or reused on a modified target, emergence of new faults and/or re-emergence of old faults is quite common. Sometimes re-emergence occurs because a fix gets lost through poor revision control practices (or simple human error in revision control). Often, a fix for a problem will be " fragil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Functional Testing
In software development, functional testing is a form of software testing that verifies whether a system meets its functional requirements.ISO/IEC/IEEE 24765:2017, "Systems and software engineering — Vocabulary", International Organization for Standardization, Geneva, Switzerland, 2017. Generally, functional testing is black-box, meaning the internal program structure is ignored (unlike for white-box testing).Kaner, Falk, Nguyen. ''Testing Computer Software''. Wiley Computer Publishing, 1999, p. 42. . Sometimes, functional testing is a quality assurance (QA) process.Prasad, Dr. K.V.K.K. (2008) ''ISTQB Certification Study Guide'', Wiley, , p. vi As a form of system testing, functional testing tests slices of functionality of the whole system. Despite similar naming, functional testing is not testing the code of a single function. The concept of incorporating testing earlier in the delivery cycle is not restricted to functional testing. Types Functional testing include ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Test Case
In software engineering, a test case is a specification of the inputs, execution conditions, testing procedure, and expected results that define a single test to be executed to achieve a particular software testing objective, such as to exercise a particular program path or to verify compliance with a specific requirement. Test cases underlie testing that is methodical rather than haphazard. A battery of test cases can be built to produce the desired coverage of the software being tested. Formally defined test cases allow the same tests to be run repeatedly against successive versions of the software, allowing for effective and consistent regression testing. Formal test cases In order to fully test that all the requirements of an application are met, there must be at least two test cases for each requirement: one positive test and one negative test. If a requirement has sub-requirements, each sub-requirement must have at least two test cases. Keeping track of the link between ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
System Integration Testing
System integration testing (SIT) involves the overall testing of a complete system of many subsystem components or elements. The system under test may be composed of electromechanical or computer hardware, or software, or hardware with embedded software, or hardware/software with human-in-the-loop testing. SIT is typically performed on a larger integrated system of components and subassemblies that have previously undergone subsystem testing. SIT consists, initially, of the "process of assembling the constituent parts of a system in a logical, cost-effective way, comprehensively checking system execution (all nominal and exceptional paths), and including a full functional check-out." Following integration, system test is a process of " verifying that the system meets its requirements, and validating that the system performs in accordance with the customer or user expectations." In technology product development, the beginning of system integration testing is often the fi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Mythical Man Month
''The Mythical Man-Month: Essays on Software Engineering'' is a book on software engineering and project management by Fred Brooks first published in 1975, with subsequent editions in 1982 and 1995. Its central theme is that adding manpower to a software project that is behind schedule delays it even longer. This idea is known as Brooks's law, and is presented along with the second-system effect and advocacy of prototyping. Brooks's observations are based on his experiences at IBM while managing the development of OS/360. He had added more programmers to a project falling behind schedule, a decision that he would later conclude had, counter-intuitively, delayed the project even further. He also made the mistake of asserting that one project—involved in writing an ALGOL compiler—would require six months, regardless of the number of workers involved (it required longer). The tendency for managers to repeat such errors in project development led Brooks to quip that his book is ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fred Brooks
Frederick Phillips Brooks Jr. (April 19, 1931 – November 17, 2022) was an American computer architect, software engineer, and computer scientist, best known for managing development of IBM's System/360 family of mainframe computers and the OS/360 software support package, then later writing candidly about those experiences in his seminal book '' The Mythical Man-Month''. In 1976, Brooks was elected to the National Academy of Engineering for "contributions to computer system design and the development of academic programs in computer sciences". Brooks received many awards, including the National Medal of Technology in 1985 and the Turing Award in 1999. Education Born on April 19, 1931, in Durham, North Carolina, he attended Duke University, graduating in 1953 with a Bachelor of Science degree in physics, and he received a Ph.D. in applied mathematics (computer science) from Harvard University in 1956, supervised by Howard Aiken. Brooks served as the graduate teaching a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Compiler
In computing, a compiler is a computer program that Translator (computing), translates computer code written in one programming language (the ''source'' language) into another language (the ''target'' language). The name "compiler" is primarily used for programs that translate source code from a high-level programming language to a lower level language, low-level programming language (e.g. assembly language, object code, or machine code) to create an executable program.Compilers: Principles, Techniques, and Tools by Alfred V. Aho, Ravi Sethi, Jeffrey D. Ullman - Second Edition, 2007 There are many different types of compilers which produce output in different useful forms. A ''cross-compiler'' produces code for a different Central processing unit, CPU or operating system than the one on which the cross-compiler itself runs. A ''bootstrap compiler'' is often a temporary compiler, used for compiling a more permanent or better optimised compiler for a language. Related software ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Correctness (computer Science)
In theoretical computer science, an algorithm is correct with respect to a program specification, specification if it behaves as specified. Best explored is ''functional'' correctness, which refers to the input–output behavior of the algorithm: for each input it produces an output satisfying the specification. Within the latter notion, ''partial correctness'', requiring that ''if'' an answer is returned it will be correct, is distinguished from ''total correctness'', which additionally requires that an answer ''is'' eventually returned, i.e. the algorithm terminates. Correspondingly, to mathematical proof, prove a program's total correctness, it is sufficient to prove its partial correctness, and its termination. The latter kind of proof (termination proof) can never be fully automated, since the halting problem is undecidable problem, undecidable. For example, successively searching through integers 1, 2, 3, … to see if we can find an example of some phenomenon—say an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Black Box
In science, computing, and engineering, a black box is a system which can be viewed in terms of its inputs and outputs (or transfer characteristics), without any knowledge of its internal workings. Its implementation is "opaque" (black). The term can be used to refer to many inner workings, such as those of a transistor, an engine, an algorithm, the human brain, or an institution or government. To analyze an open system with a typical "black box approach", only the behavior of the stimulus/response will be accounted for, to infer the (unknown) ''box''. The usual representation of this "black box system" is a data flow diagram centered in the box. The opposite of a black box is a system where the inner components or logic are available for inspection, which is most commonly referred to as a white box (sometimes also known as a "clear box" or a "glass box"). History The modern meaning of the term "black box" seems to have entered the English language around 1945. In electroni ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Overhead (business)
In business, an overhead or overhead expense is an ongoing expense of operating a business. Overheads are the expenditure which cannot be conveniently traced to or identified with any particular revenue unit, unlike operating expenses such as raw material and labor. Overheads cannot be immediately associated with the products or services being offered, and so do not directly generate profits. However, they are still vital to business operations as they provide critical support for the business to carry out profit making activities. One example would be the rent for a factory, which allows workers to manufacture products which can then be sold for a profit. Such expenses are incurred for output generally and not for particular work order; e.g., wages paid to watch and ward staff, heating and lighting expenses of factory, etc. Overheads are an important cost element, alongside direct materials and direct labor. Overheads are often related to accounting concepts such as fixed costs and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Agile Software Development
Agile software development is an umbrella term for approaches to software development, developing software that reflect the values and principles agreed upon by ''The Agile Alliance'', a group of 17 software practitioners, in 2001. As documented in their ''Manifesto for Agile Software Development'' the practitioners value: * Individuals and interactions over processes and tools * Working software over comprehensive documentation * Customer collaboration over contract negotiation * Responding to change over following a plan The practitioners cite inspiration from new practices at the time including extreme programming, Scrum (software development), scrum, dynamic systems development method, adaptive software development and being sympathetic to the need for an alternative to documentation driven, heavyweight software development processes. Many software development practices emerged from the agile mindset. These agile-based practices, sometimes called ''Agile'' (with a capital ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unit Testing
Unit testing, component or module testing, is a form of software testing by which isolated source code is tested to validate expected behavior. Unit testing describes tests that are run at the unit-level to contrast testing at the Integration testing, integration or System testing, system level. History Unit testing, as a principle for testing separately smaller parts of large software systems, dates back to the early days of software engineering. In June 1956 at US Navy's Symposium on Advanced Programming Methods for Digital Computers, H.D. Benington presented the Semi-Automatic Ground Environment, SAGE project. It featured a specification-based approach where the coding phase was followed by "parameter testing" to validate component subprograms against their specification, followed then by an "assembly testing" for parts put together. In 1964, a similar approach is described for the software of the Project Mercury, Mercury project, where individual units developed by dif ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Software Quality Assurance
Software quality assurance (SQA) is a means and practice of monitoring all software engineering processes, methods, and work products to ensure compliance against defined standards. It may include ensuring conformance to standards or models, such as ISO/IEC 9126 (now superseded by ISO 25010), SPICE or CMMI. It includes standards and procedures that managers, administrators or developers may use to review and audit software products and activities to verify that the software meets quality criteria which link to standards. SQA encompasses the entire software development process, including requirements engineering, software design, coding, code reviews, source code control, software configuration management, testing, release management and software integration. It is organized into goals, commitments, abilities, activities, measurements, verification and validation. Purpose SQA involves a three-pronged approach: * Organization-wide policies, procedures and standar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
