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Cleanroom Software Engineering
The cleanroom software engineering process is a software development process intended to produce software with a certifiable level of reliability. The central principles are software development based on formal methods, incremental implementation under statistical quality control, and statistically sound testing. History The cleanroom process was originally developed by Harlan Mills and several of his colleagues including Alan Hevner at IBM. The cleanroom process first saw use in the mid to late 1980s. Demonstration projects within the military began in the early 1990s. Recent work on the cleanroom process has examined fusing cleanroom with the automated verification capabilities provided by specifications expressed in CSP. Philosophy The focus of the cleanroom process is on defect prevention rather than defect removal. The name "cleanroom" was chosen to evoke the cleanrooms used in the electronics industry to prevent the introduction of defects during the fabrication of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Software Development Process
In software engineering, a software development process or software development life cycle (SDLC) is a process of planning and managing software development. It typically involves dividing software development work into smaller, parallel, or sequential steps or sub-processes to improve design and/or product management. The methodology may include the pre-definition of specific deliverables and artifacts that are created and completed by a project team to develop or maintain an application. Most modern development processes can be vaguely described as agile. Other methodologies include waterfall, prototyping, iterative and incremental development, spiral development, rapid application development, and extreme programming. A life-cycle "model" is sometimes considered a more general term for a category of methodologies and a software development "process" is a particular instance as adopted by a specific organization. For example, many specific software development processe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reliability Engineering
Reliability engineering is a sub-discipline of systems engineering that emphasizes the ability of equipment to function without failure. Reliability is defined as the probability that a product, system, or service will perform its intended function adequately for a specified period of time, OR will operate in a defined environment without failure. Reliability is closely related to availability, which is typically described as the ability of a component or system to function at a specified moment or interval of time. The ''reliability function'' is theoretically defined as the probability of success. In practice, it is calculated using different techniques, and its value ranges between 0 and 1, where 0 indicates no probability of success while 1 indicates definite success. This probability is estimated from detailed (physics of failure) analysis, previous data sets, or through reliability testing and reliability modeling. Availability, testability, maintainability, and maintenance ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Harlan Mills
Harlan D. Mills (May 14, 1919 – January 8, 1996) was professor of computer science at the Florida Institute of Technology and founder of Software Engineering Technology, Inc. of Vero Beach, Florida (since acquired by Q-Labs). Mills' contributions to software engineering have had a profound and enduring effect on education and industrial practice. Since earning his Ph.D. in Mathematics at Iowa State University in 1952, Mills led a distinguished career. As an IBM research fellow, Mills adapted existing ideas from engineering and computer science to software development. These included automata theory, the structured programming theory of Edsger Dijkstra, Robert W. Floyd, and others, and Markov chain-driven software testing. His Cleanroom software development process emphasized top-down design and formal specification. Mills contributed his ideas to the profession in six books and over fifty refereed articles in technical journals. Mills was termed a "super-programmer", ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Communicating Sequential Processes
In computer science, communicating sequential processes (CSP) is a formal language for describing patterns of interaction in concurrent systems. It is a member of the family of mathematical theories of concurrency known as process algebras, or process calculi, based on message passing via channels. CSP was highly influential in the design of the occam programming language and also influenced the design of programming languages such as Limbo, RaftLib, Erlang (programming language), Erlang, Go (programming language), Go, Crystal (programming language), Crystal, and Clojure's core.async. CSP was first described by Tony Hoare in a 1978 article, and has since evolved substantially. CSP has been practically applied in industry as a tool for formal specification, specifying and verifying the concurrent aspects of a variety of different systems, such as the T9000 Transputer, as well as a secure e-commerce system. The theory of CSP itself is also still the subject of active research, in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cleanroom
A cleanroom or clean room is an engineered space that maintains a very low concentration of airborne particulates. It is well-isolated, well-controlled from contamination, and actively cleansed. Such rooms are commonly needed for scientific research and in industrial production for all nanoscale processes, such as semiconductor device manufacturing. A cleanroom is designed to keep everything from dust to airborne organisms or vaporised particles away from it, and so from whatever material is being handled inside it. A cleanroom can also prevent the escape of materials. This is often the primary aim in hazardous biology, nuclear work, pharmaceutics, and virology. Cleanrooms typically come with a cleanliness level quantified by the number of particles per cubic meter at a predetermined molecule measure. The ambient outdoor air in a typical urban area contains 35,000,000 particles for each cubic meter in the size range 0.5 μm and bigger, equivalent to an ISO 9 certified c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electronics Industry
The electronics industry is the industry (economics), industry that produces electronic devices. It emerged in the 20th century and is today one of the largest global industries. Contemporary society uses a vast array of electronic devices that are built in factories operated by the industry, which are almost always partially automated. Electronic products are primarily assembled from metal–oxide–semiconductor (MOS) transistors and integrated circuits, the latter principally by photolithography and often on printed circuit boards. Circuit boards are assembled largely using surface-mount technology, which typically involves the automated placement of electronic parts on circuit boards using pick-and-place machines. Surface-mount technology and pick-and-place machines make it possible to assemble large numbers of circuit boards at high speed. The industry's size, the use of toxic materials, and the difficulty of recycling have led to a series of problems with electronic waste. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Semiconductor
A semiconductor is a material with electrical conductivity between that of a conductor and an insulator. Its conductivity can be modified by adding impurities (" doping") to its crystal structure. When two regions with different doping levels are present in the same crystal, they form a semiconductor junction. The behavior of charge carriers, which include electrons, ions, and electron holes, at these junctions is the basis of diodes, transistors, and most modern electronics. Some examples of semiconductors are silicon, germanium, gallium arsenide, and elements near the so-called " metalloid staircase" on the periodic table. After silicon, gallium arsenide is the second-most common semiconductor and is used in laser diodes, solar cells, microwave-frequency integrated circuits, and others. Silicon is a critical element for fabricating most electronic circuits. Semiconductor devices can display a range of different useful properties, such as passing current more easil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Formal Methods
In computer science, formal methods are mathematics, mathematically rigorous techniques for the formal specification, specification, development, Program analysis, analysis, and formal verification, verification of software and computer hardware, hardware systems. The use of formal methods for software and hardware design is motivated by the expectation that, as in other engineering disciplines, performing appropriate mathematical analysis can contribute to the reliability and robustness of a design. Formal methods employ a variety of theoretical computer science fundamentals, including logic in computer science, logic calculi, formal languages, automata theory, control theory, program semantics, type systems, and type theory. Uses Formal methods can be applied at various points through the software development process, development process. Specification Formal methods may be used to give a formal description of the system to be developed, at whatever level of detail desired. F ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Model Checking
In computer science, model checking or property checking is a method for checking whether a finite-state model of a system meets a given specification (also known as correctness). This is typically associated with hardware or software systems, where the specification contains liveness requirements (such as avoidance of livelock) as well as safety requirements (such as avoidance of states representing a system crash). In order to solve such a problem algorithmically, both the model of the system and its specification are formulated in some precise mathematical language. To this end, the problem is formulated as a task in logic, namely to check whether a structure satisfies a given logical formula. This general concept applies to many kinds of logic and many kinds of structures. A simple model-checking problem consists of verifying whether a formula in the propositional logic is satisfied by a given structure. Overview Property checking is used for verification when two ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Process Algebras
In computer science, the process calculi (or process algebras) are a diverse family of related approaches for formally modelling concurrent systems. Process calculi provide a tool for the high-level description of interactions, communications, and synchronizations between a collection of independent agents or processes. They also provide algebraic laws that allow process descriptions to be manipulated and analyzed, and permit formal reasoning about equivalences between processes (e.g., using bisimulation). Leading examples of process calculi include CSP, CCS, ACP, and LOTOS. More recent additions to the family include the π-calculus, the ambient calculus, PEPA, the fusion calculus and the join-calculus. Essential features While the variety of existing process calculi is very large (including variants that incorporate stochastic behaviour, timing information, and specializations for studying molecular interactions), there are several features that all process calculi have ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Petri Nets
A Petri net, also known as a place/transition net (PT net), is one of several mathematical modeling languages for the description of distributed systems. It is a class of discrete event dynamic system. A Petri net is a directed bipartite graph that has two types of elements: places and transitions. Place elements are depicted as white circles and transition elements are depicted as rectangles. A place can contain any number of tokens, depicted as black circles. A transition is enabled if all places connected to it as inputs contain at least one token. Some sources state that Petri nets were invented in August 1939 by Carl Adam Petri — at the age of 13 — for the purpose of describing chemical processes. Like industry standards such as UML activity diagrams, Business Process Model and Notation, and event-driven process chains, Petri nets offer a graphical notation for stepwise processes that include choice, iteration, and concurrent execution. Unlike these standards, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Box Structure Method
A box (plural: boxes) is a container with rigid sides used for the storage or transportation of its contents. Most boxes have flat, parallel, rectangular sides (typically rectangular prisms). Boxes can be very small (like a matchbox) or very large (like a shipping box for furniture) and can be used for a variety of purposes, from functional to decorative. Boxes may be made of a variety of materials, both durable (such as wood and metal) and non-durable (such as corrugated fiberboard and paperboard). Corrugated metal boxes are commonly used as shipping containers. Boxes may be closed and shut with flaps, doors, or a separate lid. They can be secured shut with adhesives, tapes, string, or more decorative or elaborately functional mechanisms, such as catches, clasps or locks. Packaging Several types of boxes are used in packaging and storage. * A corrugated box is a shipping container made from corrugated fiberboard, most commonly used to transport products from a wareho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
