Definition of software quality what is software quality. Similarly, models consisting of 12 to 15 factors, were suggested by deutsch and willis 1988 and by evans and marciniak 1987. The main objective of software engineering is to produce good quality and maintainable software in time and feasible too. Below are few quality models from the so called quality management gurus. Software quality assurance vs software quality plan.
Every software is a bit different and developers have to do slightly different things to ensure quality. Software quality assurance sqa is a set of activities for ensuring quality in software engineering processes. These include labor, hardware and software purchases or rentals, travel for meeting or testing purposes, telecommunications e. Software quality management is a process that ensures the required level of software quality is achieved when it reaches the users, so that they are satisfied by its performance. The quality of software product is important in some sensitive systems such as real time systems, control systems etc. Software reliability is the probability of failurefree software operation for a specified period of time in a specified environment. A framework for counting problems and defects september 1992 technical report william a. The components of the software quality assurance system overview 40. We use your linkedin profile and activity data to personalize ads and to show you more relevant ads. Quality quality of the software is checked to see if it meets the requirements, expectations. Mccalls quality model 1977 also called as general electrics model. For example, modularity is an attribute of the architecture of a software system. The modern read of high quality associates with software many quality factors like the following. Quality and productivity factors during software development.
The biggest factor is the experience and expertise of the developers working on the software. A quality criteria is an attribute of a quality factor that is related to software development. This case study dramatically illustrates the benefits of codelevel measurement activities. It is the set of activities which ensure processes, procedures as well as standards suitable for the project and implemented correctly.
Testability requirements deal with the testing of the software system as well as. All the software projects suffered from poor performance. Pdf software quality factors and software quality metrics to. Software quality is defined as a field of study and practice that describes the desirable attributes of software products.
To achieve this, software should be developed according to the functional and performance requirements, document development standards, and characteristics expected from professionally developed software. Software quality management tutorial tutorialspoint. However, in an activity like software development so intensive in workforce and so dependent on professionals performance, it is strange that human and social factors affecting development teams have been attracted little attention. When software is being developed in an engineering concept, some form of assurance validity must be met, this is in order to measure requirements in each stage of the sdlc. In the context of software engineering, software quality. Quality of software may be defined as the need of function and efficiency. Traditionally more effort has been devoted to technical and process aspects of software quality and productivity.
There are many factors to consider when estimating the total cost of a project. Software metric deals with the measurement of software product and. For the love of physics walter lewin may 16, 2011 duration. Ease with which the software and data can be checked for compliance with standards. It ensures that developed software meets and complies with the defined or standardized quality specifications. It mainly has 3 major representations for defining and identifying the quality of a software product, namely. Incorporating human factors into the software engineering lifecycle. We can view quality of a software product as having three dimensions. Software quality factors and software quality metrics to. Influence of human factors in software quality and. A case study thomas drake national security agency to ensure costeffective delivery of high quality software, nsa has analyzed effective quality measures applied to a sample code base of 25 million lines. Software engineering is the best choice, though with the right experience and computer knowledge, other educational paths are possible, such as computer science, information systems, or. Software reliability is also an important factor affecting system reliability.
Software quality assurance from theory to implementation daniel galin. Software quality factors and software quality metrics to enhance. The classic model of software quality factors, suggested by mccall, consists of 11 factors mccall et al. Quality characteristics are defined in the standard isoiec 9126. 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.
Spring 2005 ece450h1s software engineering ii managing software quality 1. Software quality assurance sqa is simply a way to assure quality in the software. Quality models in software engineering msritse2012. Software quality factors the various factors, which influence the software, are.
Section 5 builds an appropriate method of software quality metrics application in quality life cycle with software quality assurance. This 1992 report presents mechanisms for describing and specifying software problems and defectstwo software measures used to understand and predict software product quality and software process efficacy. A software defect can be regarded as any failure to address enduser requirements. Define the meaning of software quality and detail the factors which affects the quality not productivity of a software product.
Sqa is an ongoing process within the software development life cycle sdlc that routinely checks the developed software to ensure it meets the desired quality measures. These characteristics help evaluating the quality of software, but they do not define a guidance of constructing high quality software products. The concepts of software quality metrics expressed in this handbook contribute to a more disciplined, engineering approach to. Software quality assurance is a formal process for evaluating and documenting the quality of the work products during each stage of the. Developing methods that can produce high quality software is another fundamental goal of software engineering. Qa in software processes process variations and qa alternative to waterfall. Quality characteristics of the software can be measured with a set of attributes defined for each characteristic.
Sqa project process standards ieee software engineering standards 000. This model evaluates the software products only from the users. The purpose of this paper is to identify the importance quality in software engineering when the projects or products are developed. Early indicators of software quality are beneficial for software engineers and managers in determining the reliability of the system, estimating and prioritizing work items, focusing on areas that. Software quality is the key element of software engineering. Thus, in the quest for improving software quality, we must first understand the software quality definition. Understandability is possessed by a software product if the purpose of. In developing a software quality assurance, guide i came across a reference to software quality plan.
From early times of software engineering, attenti on to software quality has evident. The degree to which a component, system or process meets specified requirements andor usercustomer needs and. Write different software quality factors by dinesh thakur category. Software quality factors and software quality metrics to enhance software quality assurance data pdf available in current journal of applied science and technology 421 june 2014 with 5,029. Knowledge of andor work experience within the software quality assurance field is helpful but not required. Apart from the extent of the re engineering, the principal factors that affect re engineering costs are. Software quality factors and software quality metrics to enhance software quality assurance mingchang lee 1 1national kaohsiung university of applied sciences. In the context of software engineering, software quality refers to two related but distinct notions. Define what quality means for large software systems 2. The software quality management system must be audited on a regular basis servicing and support activities must be subject to the quality management system the developers must establish appropriate statistical techniques to verify the acceptability of the final product.
The process involves quality assurance, quality planning, and quality control. A software is claimed to be transportable, if it may be simply created to figure in several package environments, in several machines, with alternative code merchandise, etc. Software engineering software quality geeksforgeeks. Several models of software quality factors and their categorization have been suggested over the years. Sqa spans across the entire software development lifecycle that includes requirements management, software design, coding, testing, and release management. Software quality engineering slide part i 1 software quality engineering. Software quality assurance is the set of activities which ensure that the standards, processes and procedures are suitable for the project and implemented correctly. The recommended path toward this software engineering niche is to earn a fouryear degree. This model was mainly developed for us military to bridge the gap between users and developers. Write different software quality factors ecomputernotes. A software quality factor is a nonfunctional requirement for a software program which is not called up by the customers contract, but nevertheless is a desirable requirement which enhances the quality of the software program. The aim of the software developer is to develop high quality software within a specified time and budget.
This definition seems to be more appropriate to a different quality factor called maintainability, which will be examined later. It provides a thorough introduction for those new to software quality, as well as an opportunity to fill in any blank spots for experienced personnel. Its presence can be difficult to define, but its absence can be easy to see instantly. The lower the quality of the software and its associated documentation if any, the higher the re engineering costs. The models to evaluate the quality of software have been constructed defining the fundamental factors also called characteristics, and within each of them the sub factors. Quality and productivity factors during software development some factors that effects the quality and productivity are.