Indeed, maintenance is nearly always the longest part of a software life cycle, as it lasts … To promote the long-term development of the test-case prioritization topic, it is necessary to review and summarize it systematically. The maintainability advantage needs to be understood also as part of securing company investment in training: by providing a framework under which all simulation based trainings are hosted and managed, all the company training portfolio is made available to personnel, increasing awareness and usage and limiting the people and skills required to effectively manage all the training material. High simulation efficiency can be achieved if code optimization techniques are used to maximize the use of the target machine's data registers. In computing, scalability is a characteristic of computers, networks, algorithms, networking protocols, programs and applications. In Chapter 8 we shall analyze various standards and define the concept of safety. Moreover, quality management will be presented in Chapter 9. In this work, an expanded Weibull distribution is used which is applicable when the scale parameter is a function of time (Choi et al., 2005). In this sense the term reliability can be coupled with confidence in that it describes how users have confidence that the network and system will meet their requirements. maintainability The ability of an item, under stated conditions of use, to be retained in or restored to a state in which it can perform its required functions, when maintenance is performed under stated conditions and using prescribed procedures and resources. Philip H. Newcomb, ... Luong Nguyen, in Information Systems Transformation, 2010. TSRI and Northrop Grumman's technical solution conformed to and was compatible with GCSS-AF IF and GCSS-AF Data Services standards and requirements to the extent they have been identified and described by the respective program offices as of the date of the government's Request for Proposal. If these delay boundaries are exceeded, the visualization task fails for that application, forcing the system to use other techniques. applicable to software applications with a safety objective introduce the concept of safety level and recommend as quality management a basic technique through the application of ISO 9001:2008 [ISO 08] and pre-established and systematic techniques. It is important to keep in mind that only failures that prevent the system from performing its mission, or mission-critical failures (more on this in Chapter 2), are generally considered in this analysis. The most widely-used metrics are the ones defined by Chidamber and Kemerer (1994) and other studies (e Abreu and Melo, 1996; e Abreu, 1995). Bruce R. Maxim, Marouane Kessentini, in Software Quality Assurance, 2016. To make Maintainability Testing more effective, testers should include static analysis and reviews as these are hard to spot during dynamic testing while it is easily captured in code walkthrough and inspection. Reliability is an attribute of any computer-related component (software, or hardware, or a network, for example) that consistently performs according to its specifications. Once REMIS is fully migrated the legacy hardware will no longer need to be maintained and supported, resulting in a cost savings to the Air Force. Briefly speaking, test-case prioritization aims to schedule the execution order of test cases so as to satisfy some testing requirements. Test-case prioritization [29–65] reorders test cases in order to maximize early fault detection. Passengers (users) of the airline system expect accurate delivery of information (in this case the passengers themselves) to the destination. For example, the emphasis of a network design may be to bound delay: A system supporting point-of-sale transactions may need to guarantee delivery of customer information and completion of the transaction within 15 seconds (where the network delay is on the order of 100s of ms); a Web application can have similar requirements. The compilation time could be a severe limitation for fault simulators that require recompilation for each faulty circuit. The earliest programming languages were assembly languages, not far removed from the binary-encoded instructions directly executed by the computer. In fact, depending on the sector, a software application has a more or less long life (15 years for automotive sector, 40 or 50 years for railway and aviation sectors, 50 years for nuclear sector, etc. Hardware and software resources are also more efficiently consumed. Measuring software maintainability is non-trivial and there exists no single metric to measure it accurately. After all, the program will run perfectly well without it. ... maintainability, and reusability. An example network for native machine code generation. For example, Google engineers have witnessed a quadratic increase in their regression testing time, and the number of tests executed each day within Google already exceeds 100 million [5–7]. The maintainability of a software application is the most important attribute after safety. A code inspection checklist can find simple errors of omission and commission. Therefore, test-case prioritization does not have any fault-detection loss and has been widely studied in research and applied in practice [5, 44, 66]. Yang et al. Losing or misplacing passengers is unacceptable. The native machine code approach generates the native machine code directly without the need of compilation; this makes it a more viable solution to fault simulation. The term maintainability corresponds to the ability to update or modify the system under test. Boundary data is a pair of test data values at each end of a range: The data at the upper or lower limits of expectations that should be accepted A functionality defect is one in which the behavior of the service does not meet the requirements for the service. A reliability defect is one that might affect the running of the system. In cases involving multiple inheritances, the DIT is the maximum length from the node to the root of the tree, PF measures the degree of method overriding in the class inheritance tree. Sanaie and Schenkelberg (2013) used the following equation instead of Eq.(4). Maintainability is defined as "the relative ease and economy time and resources with which an time can be retained in or restored to a specified condition when maintenance is performed by personnel having specified skill levels, using prescribed procedures and resources, at each prescribed level of … Collectively, they affect both the utility and the life-cycle costs of a product or system. This is evident in several arguments carrying a debate whether SW development is an art or engineering [10,11]. (2013). Reliability, maintainability, and availability (RAM) are three system attributes that are of great interest to systems engineers, logisticians, and users. [29] presented a widely known industrial case to show the necessity of test-case prioritization. For example, if a service method was stubbed out during development and never implemented, it could pass all the functional tests, because it returns correct data, but it always returns the same data. an art by Donald Knuth in his classic book “The Art of Computer Programming” [9]. where F(t) = 1 − R(t) is the cumulative distribution function for failure time, G(t) for wait time, and H(t) for repair time. The process consists of finding code fragments that violate structural or semantic properties such as the ones related to coupling and complexity. In the actual implementation, each statement is replaced with the corresponding language constructs or machine instructions. A levels – To get on to a computer science related degree you will usually require at least two A levels or equivalent.Entry requirements range from CDD to AAA, with the universities and colleges most commonly asking for BBC. This course is an introduction to the fundamental concepts and terms of computer science, including algorithms, problem solving techniques, data types, concept of loops, conditional statements, modular programming, pointers, arrays, strings, basic file processing, structures and simple classes. Finally, maintainability enables to characterize the effort for evolution of a software application. (Redirected from Constant (computer science)) In computer programming, a constant is a value that cannot be altered by the program during normal execution, i.e., the value is constant. Computer science, the study of computers and computing, including their theoretical and algorithmic foundations, hardware and software, and their uses for processing information.The discipline of computer science includes the study of algorithms and data structures, computer and network design, modeling data and information processes, and artificial intelligence. probability of survival is as follows. On the surface, Computer Science seems like only programming and not much else. Accounting for as much as 80 percent of a building's life-cycle costs, operation and maintenance expenses often reach three times a building's initial construction costs. In section 5.2.3, we presented the objectives of maintenance of a software application. Maintain definition, to keep in existence or continuance; preserve; retain: to maintain good relations with neighboring countries. where z(t) is a dimensionless time that represents the degree of aging, which is defined as follows. This is generally expressed as a mean-time-to-repair (MTTR). In this context, maintainability is a function of engineering design. Introduction to maintainability. Copyright © 2020 Elsevier B.V. or its licensors or contributors. This is one of the most important properties for a critical software application. In the interim, maintaining REMIS support for the management of combat assets requires keeping pace with advancing technology and increasing global threat. A computer programmer writes source code which is ultimately converted into executable machine code. In addition, predictable delivery is also expected. (2009) indicated that unlimited repairs are impractical for most systems, and proposed an approximate calculation method, which can be applied to systems for which only a limited number of repairs are available. An introduction to the intellectual enterprises of computer science and the art of programming. The conventional method assumes that the operating condition is constant, and thus treats these parameters as constants. Therefore, in this work, we present a new survey to systematically review and summarize the test-case prioritization topic, and discuss new trends and future work. However, in a computation-intensive application we may be able to optimize the system by buffering data during periods of computing. This resource page presents a methodology that links operations and maintenance goals to the design process, and how it can be applied to any organization. This is generally expressed as a mean-time-to-repair (MTTR). Math and Computer Science are about fake things like numbers, graphs, functions, lists, etc. Many methods for reliability, availability, and maintainability (RAM) analysis are now available for project managers and engineers (Department of Defense, 2009). However, it is correct only when the system can be repaired only once. A parallel can be seen with the airline industry. In regression testing, the test cases designed for an old version are usually reused to test its latter versions to verify the code changes between versions. Words that should come to mind in addition to those are skills such as planning, analysis, documentation, and maintainability. An example is a search engine, which must support increasing numbers of users, and the number of topics it indexes. Numerical solution techniques for Volterra integral equations are also being developed as studied by Maleknejad et al. Reliability is a statistical indicator of the frequency of failure of the network and its components and represents the unscheduled outages of service. Test-case prioritization was first proposed in regression testing to deal with the trade-off between what ideal regression testing should do and what is affordable by scheduling the execution order of test cases [67]. Migration of REMIS to the GCSS-AF platform achieved both of those objectives. This follows a long tradition of using software metrics to evaluate the quality of the design including the detection of code-smells or design defects. Jean-Louis Boulanger, in Certifiable Software Applications 1, 2016. A dependable software application is a simple application. 2,531,922 already enrolled! Formally, test-case prioritization is defined as the following process: given any test suite T, test-case prioritization is to find a permutation T′ of T satisfying f(T′) ≥ f(PT), where PT represents any permutation of T and f is a function defined to map permutations of T to real numbers representing the prioritization goal [32]. Due to the characteristics of ITP (e.g., does not rely on old version information), its techniques are usually applicable to regression testing, whereas the techniques of the latter may not be applicable for the former. Computer science focuses on theory and fundamentals; ... 11 Essential attributes of good software 30/10/2014 Chapter 1 Introduction 1 1 Product characteristic Description Maintainability Software should be written in such a way so that it can evolve to meet the changing needs of customers. Understanding Nature through Observation About real things like bowling balls, black holes, antimatter, electrons, comets, etc. Among the three areas, both test-suite reduction and regression test selection exclude some test executions and may suffer from unsafe test execution (i.e., missing regression faults). During simulation, the instructions are interpreted and executed one at a time. In fact, software engineering has grown so fast in the last several decades that it has become tightly connected with all other areas of computer science (e.g., artificial intelligence, parallel processing, computer graphics, human-computer interaction, database management systems, and many others) as well as with some areas outside the traditional computer domain (such as cognitive sciences and visual arts). Furthermore, that work also proposed various basic test-case prioritization techniques, including the total and additional techniques, which are usually taken as the control techniques in the evaluation of novel test-case prioritization techniques, and still represent state-of-the-art test-case prioritization according to three recent studies [68–70]. That is, to reveal faults in the latter versions as early as possible, the reused test cases should be executed in some specified order, which is the aim of test-case prioritization. However, due to the inherent difference between alternative goals and the ultimate goal, test-case prioritization becomes more difficult. This is a very important parameter as the system is subjected to changes throughout the software life cycle. To alleviate the cost of regression testing, a large body of research has been dedicated to this area and many approaches have been proposed, such as test-suite reduction, regression test selection, and test-case prioritization [1]. Although crucial, regression testing can be extremely costly [1–3]. (2014). Defects of this type are identified easily by code inspections. where Q(t) is the cumulative distribution function for probability of being repaired, i.e. The invisibility of an attribute is the percentage of the total classes from which the attribute is not visible, MH measures the invisibilities of methods in classes. This approach offers the best portability and maintainability at the cost of reduced performance. That’s why the architecture proposed relies on the highest level of security, using authentication, encryption in all transactions and building on top of the elements that corporations use and that trusted IT providers such as Citrix recommend. 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URL: https://www.sciencedirect.com/science/article/pii/B9780123749130000081, URL: https://www.sciencedirect.com/science/article/pii/B978178548117850009X, URL: https://www.sciencedirect.com/science/article/pii/B9780123704801500025, URL: https://www.sciencedirect.com/science/article/pii/B9781785481178500064, URL: https://www.sciencedirect.com/science/article/pii/B9780128023013000028, URL: https://www.sciencedirect.com/science/article/pii/B9780123743640500151, URL: https://www.sciencedirect.com/science/article/pii/B9781558609006500063, URL: https://www.sciencedirect.com/science/article/pii/B9780444634559501082, URL: https://www.sciencedirect.com/science/article/pii/S0065245818300615, URL: https://www.sciencedirect.com/science/article/pii/B9780444639653504918, Modernization of Reliability and Maintainability Information System (REMIS) into the Global Combat Support System-Air Force (GCSS-AF) Framework*, Network Analysis, Architecture, and Design (3), An introduction to modern software quality assurance, Abran and Nguyenkim, 1993; Lawler and Kitchenham, 2003, Jiun-Lang Huang, ... Stephen F. Cauley, in, Depending on performance, portability, and, Code inspections are good at finding defects of, 24th European Symposium on Computer Aided Process Engineering, Many methods for reliability, availability, and, A Survey on Regression Test-Case Prioritization, Modern software systems keep evolving to refine software functionality and, 27th European Symposium on Computer Aided Process Engineering, WMC represents the sum of the complexities of its methods, RFC is the number of different methods that can be executed when an object of that class receives a message, Chidamber and Kemerer define Lack of Cohesion in Methods as the number of pairs of methods in a class that do not have at least one field in common minus the number of pairs of methods in the class that share at least one field. Coupling is also used to describe software as well as systems. Since the ultimate goal of regression testing is to detect regression faults, the test-case prioritization goal is usually specified as how fast the regression faults can be detected. This activity should be accompanied by a quality control and safety control. Maintainability is a statistical measure of the time to restore the system to fully operational status after it has experienced a fault. In this chapter, we summarize variations of these metrics and adaptations of procedural ones as well (Abran and Nguyenkim, 1993; Lawler and Kitchenham, 2003). The invisibility of a method is the percentage of the total classes from which the method is not visible, NLC counts the lines but excludes empty lines and comments, CBO measures the number of classes coupled to a given class. Regression test selection [17–28] aims to select and rerun only the test cases that are affected by code changes. The fourth area of advantage of the new architecture is its maintainability. By continuing you agree to the use of cookies. Availability generally means the fraction of time that the system is operational, and the instantaneous (point) availability is defined as the probability that the system is operational at a specific time, which can be formulated as follows. Maintainability is a statistical measure of the time to restore the system to fully operational status after it has experienced a fault. Furthermore, modern industry companies also suffer from regression testing cost due to the large number of accumulated test cases during software evolution. When this value is negative, the metric value is set to 0, AH measures the invisibilities of attributes in classes. Technical benefits of modernizing the REMIS software have been identified by the ability to interface with COTS products to replace existing custom code in the case of Increment-2 where the REMIS Standard Reports were converted to Cognos ReportNet reports. Yiling Lou, ... Dan Hao, in Advances in Computers, 2019. But what if those costs could be alleviated - and performance optimized - by encouraging facility professionals to provide input during the design phase of the project? It is essential to limit the complexity of the software application to the basic minimum. In the interpreted code approach, the target machine is a software emulator. More about programming than computer science, but it does talk a lot about and show some custom algorithms (it's more about programming-in-the-small, though it does talk about some big picture too), also it is old and out of print (last I checked), but I thought it was … Measuring software maintainability is a very important parameter as the final client would request to... Keep evolving to refine software functionality and maintainability, and design ( )... Electronic design Automation, 2009 are crossed, passengers are likely to higher-level! 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