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Software Entropy
Software entropy is the idea that software eventually rots as it is changed if sufficient care is not taken to maintain coherence with product design and established design principles. The common usage is only tangentially related to entropy as defined in classical thermodynamics and statistical physics. Another aspect can be found in what is perceived to be a decay in the quality of otherwise static software that is the result of the inevitable changes to its environment, that often occur as operating systems and other components are upgraded or retired. History A work on software engineering by Ivar Jacobson et al, in 1992 describes software entropy as follows: :''The second law of thermodynamics, in principle, states that a closed system's disorder cannot be reduced, it can only remain unchanged or increase. A measure of this disorder is entropy. This law also seems plausible for software systems; as a system is modified, its disorder, or entropy, tends to increase. This ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Software Rot
Software rot (bit rot, code rot, software erosion, software decay, or software entropy) is either a slow deterioration of software quality over time or its diminishing responsiveness that will eventually lead to software becoming faulty, unusable, or in need of upgrade. This is not a physical phenomenon: the software does not actually decay, but rather suffers from a lack of being responsive and updated with respect to the changing environment in which it resides. The '' Jargon File'', a compendium of hacker lore, defines "bit rot" as a jocular explanation for the degradation of a software program over time even if "nothing has changed"; the idea behind this is almost as if the bits that make up the program were subject to radioactive decay. Causes Several factors are responsible for software rot, including changes to the environment in which the software operates, degradation of compatibility between parts of the software itself, and the appearance of bugs in unused or rarely ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Domain Knowledge
Domain knowledge is knowledge of a specific, specialized discipline or field, in contrast to general (or domain-independent) knowledge. The term is often used in reference to a more general discipline—for example, in describing a software engineer who has general knowledge of computer programming as well as domain knowledge about developing programs for a particular industry. People with domain knowledge are often regarded as specialists or experts in their field. Knowledge capture In software engineering, ''domain knowledge'' is knowledge about the environment in which the target system operates, for example, software agents. Domain knowledge usually must be learned from software users in the domain (as domain specialists/experts), rather than from software developers. It may include user workflows, data pipelines, business policies, configurations and constraints and is crucial in the development of a software application. Expert's domain knowledge (frequently informal and i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Software Quality
In the context of software engineering, software quality refers to two related but distinct notions: * Software functional quality reflects how well it complies with or conforms to a given design, based on functional requirements or specifications. That attribute can also be described as the fitness for purpose of a piece of software or how it compares to competitors in the marketplace as a worthwhile product. It is the degree to which the correct software was produced. * Software structural quality refers to how it meets non-functional requirements that support the delivery of the functional requirements, such as robustness or maintainability. It has a lot more to do with the degree to which the software works as needed. Many aspects of structural quality can be evaluated only statically through the analysis of the software inner structure, its source code (see Software metrics), at the unit level, system level (sometimes referred to as end-to-end testing), which is in eff ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Software Metrics
In software engineering and development, a software metric is a standard of measure of a degree to which a software system or process possesses some property. Even if a metric is not a measurement (metrics are functions, while measurements are the numbers obtained by the application of metrics), often the two terms are used as synonyms. Since quantitative measurements are essential in all sciences, there is a continuous effort by computer science practitioners and theoreticians to bring similar approaches to software development. The goal is obtaining objective, reproducible and quantifiable measurements, which may have numerous valuable applications in schedule and budget planning, cost estimation, quality assurance, testing, software debugging, software performance optimization, and optimal personnel task assignments. Common software measurements Common software measurements include: * ABC Software Metric * Balanced scorecard * Bugs per line of code * Code coverage * Coh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metaphors
A metaphor is a figure of speech that, for rhetorical effect, directly refers to one thing by mentioning another. It may provide (or obscure) clarity or identify hidden similarities between two different ideas. Metaphors are often compared with other types of figurative language, such as antithesis, hyperbole, metonymy, and simile. One of the most commonly cited examples of a metaphor in English literature comes from the " All the world's a stage" monologue from '' As You Like It'': All the world's a stage, And all the men and women merely players; They have their exits and their entrances And one man in his time plays many parts, His Acts being seven ages. At first, the infant... :—William Shakespeare, '' As You Like It'', 2/7 This quotation expresses a metaphor because the world is not literally a stage, and most humans are not literally actors and actresses playing roles. By asserting that the world is a stage, Shakespeare uses points of comparison between the world an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Algorithmic Information Theory
Algorithmic information theory (AIT) is a branch of theoretical computer science that concerns itself with the relationship between computation and information of computably generated objects (as opposed to stochastically generated), such as strings or any other data structure. In other words, it is shown within algorithmic information theory that computational incompressibility "mimics" (except for a constant that only depends on the chosen universal programming language) the relations or inequalities found in information theory. According to Gregory Chaitin, it is "the result of putting Shannon's information theory and Turing's computability theory into a cocktail shaker and shaking vigorously." Besides the formalization of a universal measure for irreducible information content of computably generated objects, some main achievements of AIT were to show that: in fact algorithmic complexity follows (in the self-delimited case) the same inequalities (except for a constant) th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fail-fast
In systems design, a fail-fast system is one which immediately reports at its interface any condition that is likely to indicate a failure. Fail-fast systems are usually designed to stop normal operation rather than attempt to continue a possibly flawed process. Such designs often check the system's state at several points in an operation, so any failures can be detected early. The responsibility of a fail-fast module is detecting errors, then letting the next-highest level of the system handle them. Hardware and software Fail-fast systems or modules are desirable in several circumstances: * Fail-fast architectures are based on an error handling policy where any detected error or non-contemplated state makes the system fail (fast). In some sense the error handling policy is the opposite of that used in a fault-tolerant system. In a fault-tolerant system a error handling policy is established to have redundant components and move computation requests to alive components when some ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Software Rot
Software rot (bit rot, code rot, software erosion, software decay, or software entropy) is either a slow deterioration of software quality over time or its diminishing responsiveness that will eventually lead to software becoming faulty, unusable, or in need of upgrade. This is not a physical phenomenon: the software does not actually decay, but rather suffers from a lack of being responsive and updated with respect to the changing environment in which it resides. The '' Jargon File'', a compendium of hacker lore, defines "bit rot" as a jocular explanation for the degradation of a software program over time even if "nothing has changed"; the idea behind this is almost as if the bits that make up the program were subject to radioactive decay. Causes Several factors are responsible for software rot, including changes to the environment in which the software operates, degradation of compatibility between parts of the software itself, and the appearance of bugs in unused or rarely ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Software Brittleness
In computer programming and software engineering, software brittleness is the increased difficulty in fixing older software that may appear reliable, but actually fails badly when presented with unusual data or altered in a seemingly minor way. The phrase is derived from analogies to brittleness in metalworking. Causes When software is new, it is very malleable; it can be formed to be whatever is wanted by the implementers. But as the software in a given project grows larger and larger, and develops a larger base of users with long experience with the software, it becomes less and less malleable. Like a metal that has been work-hardened, the software becomes a legacy system, brittle and unable to be easily maintained without fracturing the entire system. Brittleness in software can be caused by algorithms that do not work well for the full range of input data. A good example is an algorithm that allows a divide by zero to occur, or a curve-fitting equation that is used to extrap ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Software Bloat
Software bloat is a process whereby successive versions of a computer program become perceptibly slower, use more memory, disk space or processing power, or have higher hardware requirements than the previous version, while making only dubious user-perceptible improvements or suffering from feature creep. The term is not applied consistently; it is often used as a pejorative by end users (bloatware) to describe undesired user interface changes even if those changes had little or no effect on the hardware requirements. In long-lived software, perceived bloat can occur from the software servicing a large, diverse marketplace with many differing requirements. Most end users will feel they only need some limited subset of the available functions, and will regard the others as unnecessary bloat, even if end users with different requirements require those functions. Actual (measurable) bloat can occur due to de-emphasising algorithmic efficiency in favour of other concerns like develope ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Feature Creep
Feature creep is the excessive ongoing expansion or addition of new features in a product, especially in computer software, video games and consumer and business electronics. These extra features go beyond the basic function of the product and can result in software bloat and over-complication, rather than simple design. The definition of what qualifies as "feature creep" does vary among end users, where what is perceived as such by some users may be considered practical functionality by others. Causes The most common cause of feature creep is the desire to provide the consumer with a more useful or desirable product, in order to increase sales or distribution. However, once the product reaches the point at which it does everything that it is designed to do, the manufacturer is left with the choice between adding functions some users might consider unneeded (sometimes at the cost of efficiency), and sticking with the old version (at the cost of a perceived lack of improvemen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Code Refactoring
In computer programming and software design, code refactoring is the process of restructuring existing computer code—changing the '' factoring''—without changing its external behavior. Refactoring is intended to improve the design, structure, and/or implementation of the software (its '' non-functional'' attributes), while preserving its functionality. Potential advantages of refactoring may include improved code readability and reduced complexity; these can improve the source codes maintainability and create a simpler, cleaner, or more expressive internal architecture or object model to improve extensibility. Another potential goal for refactoring is improved performance; software engineers face an ongoing challenge to write programs that perform faster or use less memory. Typically, refactoring applies a series of standardized basic ''micro-refactorings'', each of which is (usually) a tiny change in a computer program's source code that either preserves the behavior of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
