Measuring software maintainability relies on a set of metrics that may be combined in a software maintainability function. The methodology may include the predefinition of specific deliverables and artifacts that. Pdf how to effectively define and measure maintainability. Software engineering stack exchange is a question and answer site for professionals, academics, and students working within the systems development life cycle. Maintainability is defined as the ease with which a system can be maintained. We quote the ieee standard glossary of software engineering terminology.
A common perception of maintenance is that it merely involves fixing defects. A definition of maintainability with a few examples. Empirical software engineering and measurements, 2009, pp. Introduction to maintainability the concept of maintainability encompasses. Closely related concepts in the software engineering domain are evolvability, modifiability, technical debt, and code smells. Tmde requirements will be coordinated with the executive director, tmde activity.
They supply a measurement for reducing application complexity, improving quality, and moderating risk as an application is created, enhanced, or maintained. The caveat with measuring maintainability is that you are attempting to predict the future. Reliability, availability, and maintainability ram or rma are system design attributes that have significant impacts on the sustainment or total life cycle costs lcc of a developed system. Developing maintainable software software sustainability.
Developing maintainable software helps reduce technical debt. Measurements of software maintainability semantic scholar. Pdf measurement model of software requirements derived. Overall, concept mapping provides a systematic, structured, and repeatable method for developing constructs and measures, not only of maintainability, but also of software engineering phenomena in. Collectively, they affect both the utility and the lifecycle costs of a product or system. Indirect measures include products like functionality, quality, complexity, reliability, maintainability, and many more.
This document is a first step towards the construction of a maintainability prediction model. It is also known as a software development life cycle sdlc. To be effective software engineers or software managers, we must be able to control software development practice. Measuring software maintainability is nontrivial as there is no single metric to state if one application is more maintainable than the other and there is no single tool that can analyze your code repository and provide you with an accurate answer either. Maintainability has previously been described mainlyin two ways, either informally or as a function of directly measurable attributes. Role of metrics and measurement in software development the terms measure, measurement, and metrics are often used interchangeably, it is important to note the subtle differences between them. Top 10 productivity metrics for software development infopulse. Because measure can be used either as a noun or a verb, definitions of the term can become confusing. Since maintenance costs eclipse other software engineering activities by large amount, it is imperative to answer the following question.
Software engineering software reliability measurement. Various activities carried out during maintenance include the addition of new features, deletion of obsolete code, correction of errors, etc. Maintainability refers to the ease with which you can repair, improve and understand software code. It is often described as the fitness for purpose of a piece of software. The ease with which a software system or component can be modified to correct faults, improve performance or other attributes, or adapt to a changed environment. The research objective is the early specification and measurement of softwarefur derived from systemnfr, using as a basis the systems and software engineering standards.
A software maintainability measurement is a rating used to assess the amount of effort or resources currently committed to an application. Automatically measuring the maintainability of service. The maintainability index is calculated with certain formulae from linesofcode measures, mccabe measures and halstead. An essential part of keeping a softwares maintainability at a desired level or systematically improving its maintainability is to measure the progress and to nd the parts of code whose improvement would have the biggest a. Introduction to software engineeringquality wikibooks. There are many programmed solutions offer an accurate, objective way to measure each program. The narrative of the tutorial is augmented with illustrative solved problems. It identifies a set of software measures based on correlations published in empirical studies. A software maintainability measurement is a rating used to assess the. As the pioneer in software reliability engineering, john musa is rich in publications. Experience with performing reliability predictions using relex or like software. The maintainability of a system can be measured in.
Software maintenance in software engineering is the modification of a software product after delivery to correct faults, to improve performance or other attributes a common perception of maintenance is that it is merely fixing bugs. The origins of contemporary reliability engineering can be traced to world war ii. Measurement, prediction, application, mcgrawhill book company, 1987, isbn 007044093x. Therefore, both software and hardware are addressed in this tutorial in an integrated fashion. There exist metrics that can help developers measure and analyze the maintainability level of a project objectively. Why is it important to measure maintainability and what are. When equipped with relevant data, a manager can also identify project bottlenecks early and effectively. Maintainability is a measure of the ease with which a software system can be. Introduction to software engineeringdeploymentmaintenance. In software engineering, software maintenance is one of the most expensive and timeconsuming activities.
The following is an excerpt on maintainability and availability from the reliability engineering handbook by bryan dodson and dennis nolan, a qa publishing, llc. However, studies and surveys over the years have indicated that the majority, over 80%, of the maintenance effort is used for noncorrective actions pigosky 1997. For a give piece of code come up with an idea of a perfect design. How to effectively define and measure maintainability. How to effectively define and measure maintainability markus pizka and florian dei. Maintainability is a measure of the ease and rapidity with which a system or equipment can be restored to operational status following a failure. In the context of software engineering, software quality measures how well software is designed quality of design, and how well the software conforms to that design quality of conformance, although there are several different definitions. Maintainability means fixing, updating, servicing and to modify the system or update the software for performance improvements or for the correction of faults. Measuring software maintainability quandary peak research. Musa, anthony iannino, and kazuhira okumoto, software reliability.
Software measurement is a baseline component of good software engineering. Adding automation for quick, accurate measurement results. Addition of new functionality or the adaptation of software to meet new requirements for the customer needs. The standard definition of reliability is the probability of zero. Keep your code clean with these essential tips for software quality. Software maintainability is defined as the ease with which a software system or a component can be modified, to correct faults, improve performance or other attributes, or adapt to a changed environment. However, one study indicated that over 80% of maintenance effort is used for noncorrective actions. An operational measure of effectiveness a characteristic of design an engineering spe cialty that supports design a cost driver a planned activ ity in each stage of product lifecycle 2 introduction cont. Several models of software quality factors and their categorization have been suggested over the years. May 28, 2017 software maintainability is defined as the ease with which a software system or a component can be modified, to correct faults, improve performance or other attributes, or adapt to a changed environment.
Software engineering software reliability measurement techniques with software engineering tutorial, models, engineering, software development life cycle, sdlc, requirement engineering, waterfall model, spiral model, rapid application development model, rad, software management, etc. It is an internal attribute of the system which cannot be measured directly. Master thesis a model for measuring maintainability based on. Software maintenance is a phase in the software development cycle that starts after the customer has received the product. The software maintainability measurement is used to measure the effect done. Maintainability are the relative costs of fixing, updating, extending, operating and servicing an entity over its lifetime. Implementation, measurement and management jones, james on. The classic model of software quality factors, suggested by mccall, consists of 11 factors mccall et al. In engineering, maintainability is the ease with which a product can be maintained in order to. An aggregated measure of software quality can be computed through a qualitative or a quantitative scoring scheme or a mix of both and then a weighting system reflecting the priorities. This paper explains a new and more effective way to construct software product quality models. Software reliability electrical and computer engineering at.
You can understand exactly when your development team does their best work and what factors contribute to that. Maintainability is a multifaceted quality attribute each of the facets must be analyzed to objectively measure it. Measuring software maintainability is nontrivial and there exists no single metric to measure it accurately. Function points are used to compute a functional size measurement fsm of software. Software maintenance in software engineering is the modification of a software product after delivery to correct faults, to improve performance or other attributes.
Software quality measurement quantifies to what extent a software program or system rates along each of these five dimensions. An aggregated measure of software quality can be computed through a qualitative or a quantitative scoring scheme or a mix of both and then a. The key design principle is the strict separation of. The key challenge with software maintainability measurement is that maintainability cannot be measured directly. The focus of this study is to evaluate software maintainability. Reliability, availability, and maintainability the mitre. Also, measurement is used by software engineers to gain insight into the design and development of the work products. Generally, software measurement is considered as a management tool which if conducted in an effective manner, helps the project manager and the entire software team to take. For example, maintainability but each of the factors is to be measured to check for the content and the quality control. Therefore, predictive models are based on indirect measures. Additionally, the ram attributes impact the ability to perform the intended mission and affect overall mission success.
The research objective is the early specification and measurement of software fur derived from systemnfr, using as a basis the systems and software engineering standards. Use of test measurement and diagnostic equipment tmde and builtin test equipment bite for hardware systems diagnosis and built in test bit for software system diagnosis will be considered during design and development. Maintainability also includes the addition of new functionality or the adaptation of software to meet new requirements for the customer needs. An entity with relatively low costs in these areas is considered maintainable whereas an entity with high costs may be considered unmaintainable or high maintenance. Software maintenance is an expensive activity that consumes a major portion of the cost of the total project. Reliability maintainability engineer jobs, employment. Maintainability wikimili, the best wikipedia reader. Maintainability can be defined as the ease with which a software product can be modified to correct errors, to meet new requirements, to make future maintenance easier, or adapt to the changed environment. Introduction to maintainability university of tennessee. A software maintainability prediction model enables organizations to predict the maintainability of their software systems, thus providing a means to.
Reliability, availability, and maintainability sebok. The maintainability testing shall be specified in terms of the effort required to effect a change under each of the following four categories. Software maintainability free demo video explanation. Every product of the life cycle is measured by at least one metric. Pdf measurement model of software requirements derived from. The study was targeted at the software quality attribute of maintainability as opposed to the process of software maintenance.
Bass player domotica software architect hardware hacker infrastructure engineer. Automatically measuring the maintainability of service and microservicebased systems. Automated solutions offer an accurate, objective way to measure each program. The cost of a single unit is calculated from past projects. Measurement helps in estimation, quality control, productivity assessment and project control throughout a software project. Reliability, maintainability, and availability ram are three system attributes that are of great interest to systems engineers, logisticians, and users. Top 10 productivity metrics for software development. In software engineering, these activities are known as software maintenance cf. Automatically measuring the maintainability of service and. Software metrics, halstead measure, maintainability. An essential part of keeping a softwares maintainability at a desired level or systematically improving its maintainability is to measure the progress and to nd the parts of code whose improvement would have the biggest a ect on the overall maintainability. Instead, one can measure maintenance process attributes, such as. Software that is written without maintainability in mind requires about four times as much effort to maintain than it did to develop. Cost factors that re ect features of the software process, such as development.
Maintainability testing shall use a model of the maintainability requirements of the softwaresystem. In addition, measurement assists in strategic decisionmaking as a project proceeds. The recommended practice ieee p1633 is a composite of models and tools and describes the what and how of. For this reason, many applications are replaced simply because the overhead to modify them becomes prohibitive. In software engineering, a software development process is the process of dividing software development work into distinct phases to improve design, product management, and project management. Software maintainability means the ease with which these operations can be carried out. Seven source code metrics can be computed by commercial tools. Maintainability and availability what is reliability. Software reliability electrical and computer engineering. Why is it important to measure maintainability and what.
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