Increased software complexity means that maintenance and enhancement projects will take longer, will cost more, and will result in more errors. It differs from hardware reliability in that it reflects the design perfection, rather than manufacturing perfection. Instead, one can measure maintenance process attributes, such as. Software maintenance is an expensive activity that consumes a major portion of the cost of the total project. As a system is developed, it is likely that the number of entities will grow, and with this the number of interactions between those entities. Software maintainability free demo video explanation. For this reason, many applications are replaced simply because the overhead to modify them becomes prohibitive. Computes a score of how maintainable a program is, based on a combination of cyclomatic complexity, halstead volume, normalized by the number of lines of. A measure of effort must include time, resources and expertise. Software reliability is also an important factor affecting system reliability. Ability of a computer program to be retained in its original form, and to be restored to that form in case of a failure.
Although crucial, regression testing can be extremely costly. Code metrics is a set of software measures that provide developers better insight into the code they are developing. In general, maintainability index relies on many factors. In software programming, as the design of software is realized, the number of elements and their interconnections gradually emerge to be huge, which becomes too difficult to understand at once. Measures the number of linearlyindependent paths through a program module control flow. The increased complexity of modern software applications also increases the difficulty of making the code reliable and maintainable. Tmde requirements will be coordinated with the executive director, tmde activity. Maintainability testing is not the same as maintenance testing which is testing software that has been modified. Software reliability is the probability of failurefree software operation for a specified period of time in a specified environment. The focus of this study is to evaluate software maintainability.
Software maintenance in software engineering is the modification of a software product after delivery to correct faults, to improve performance or other attributes. In 1991 oman and hagemeister introduced a composite metric for quantifying software maintainability. According to the ieee, software maintainability is defined as 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 1. Software maintainability index revisited researchgate.
The importance of maintaining software updates the main benefits of maintaining software updates are that security remains on point, usability is firing on all cylinders, and your software is compatible with other all the software you use. Designing dataintensive applications maintainability. As the project grows and technology evolves, complexity and the list of issues grow. Software complexity is the measure of how difficult the pl ogram is to comprehend and work with. Modeling designcoding factors that drive maintainability. This maintainability index mi has evolved into numerous variants and has been successfully applied to a number of. Abstractsoftware metrics is one of the wellknown topics of research in software. Maintainability is defined as the ease with which a system can be maintained. This paper discusses the results of allocated to each subsystem based on their complexity and reliability and maintainability reallocations made for the gsdo subsystems as the program nears the end of its design phase. Various activities carried out during maintenance include the addition of new features, deletion of obsolete code, correction of errors, etc. Chug, software maintainability prediction using machine learning algorithms, softw. Does it make sense to compute cyclomatic complexitylines of. However, existing definitions of maintainability, such as the halstead volume, mccabes cyclomatic complexity or the sei maintainability index provide a very poor understanding of what maintainability is how it. In more extreme cases, it can make modifying the software virtually impossible.
Models are proposed for estimating the economic impacts of software complexity and for identifying the factors which affect a systems complexity. Cyclomatic complexity is a software metric used to indicate the complexity of a program. Calculate code metrics visual studio microsoft docs. Models are proposed for estimating the economic impacts of. Maintainability is a multifaceted quality attribute each of the facets must be analyzed to objectively measure it. Code is passed to escomplex in the form of syntax trees that have been generated with esprima, the popular javascript parser. Maintainability can be either a static form of testing, i. Maintainability is an estimate of technical debt in the repo based on a standardized 10point assessment of duplication, cyclomatic complexity, cognitive complexity, and structural issues for every technical debt issue we identify during our 10point inspection, we estimate a. Explosion of state space, tight coupling, spaghetti of dependencies, inconsistent coding standards such as naming and terminology, hacking in performance improvements, code to handle one off edge cases sprinkled throughout. Unlike cyclomatic complexity and halstead volume, the.
Pdf software complexity and maintainability researchgate. Maintainability refers to the ease with which you can repair, improve and understand software code. Developing maintainable software helps reduce technical debt. Does it make sense to compute cyclomatic complexitylines. Software maintainability means the ease with which these operations can be carried out. Measuring software maintainability is nontrivial and there exists no single metric to measure it accurately. The term complexity stands for state of events or things, which have multiple interconnected links and highly complicated structures.
For example, in visual studio, it rely on cyclomatic complexity, depth of inheritance, class coupling and lines of. Closely related concepts in the software engineering domain are evolvability, modifiability, technical debt, and code smells. Maintainability is an estimate of technical debt in the repo based on a standardized 10point assessment of duplication, cyclomatic complexity, cognitive complexity, and structural issues. Software that is written without maintainability in mind requires about four times as much effort to maintain than it did to develop. Software complexity and maintainability proceedings of the tenth. Software maintainability is important because it is approximately 75% of the cost related to a project. Software complexity, deals with how difficult a program is to comprehend and work with 3. Software complexity is closely related with modularity, information hiding, coupling and cohesion. According to several commentators, there is a distinction between the terms complex and complicated. Citeseerx document details isaac councill, lee giles, pradeep teregowda. Software design for maintainability, page 1 of 6 technique dfe6 page dfe23 technique apply maintainability concepts to development of software in the early. It is an internal attribute of the system which cannot be measured directly.
Development teams can identify potential risks, understand the current state of a project, and track progress during software development. This paper discusses a number of software complexity metrics reported in the last few years and examines the applicability of these complexity metrics to form a software maintainability point of view. Modern software systems keep evolving to refine software functionality and maintainability, as well as fixing software flaws. Wmfp automatically measures the complexity of existing source code. Essentially, with cyclomatic complexity, higher numbers are bad and lower numbers are good. Collectively, they affect economic lifecycle costs of a system and its utility. This is why future maintainability should be at the top of developers minds when architecting and developing software applications. Manageabilityhow efficiently and easily a software system can be monitored and maintained to keep the system performing, secure, and running smoothly. It is a quantitative measure of the number of linearly independent paths through a programs source code.
The mccabe complexity is one of the more widelyaccepted software metrics, it is intended to be independent of language and language format. Reducing complexity improves maintainability of software. Maintainabilitythe 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 ieee 1990. Materiel systems also include, but are not limited to, standalone or embedded automatic data pro. This document is a first step towards the construction of a maintainability prediction model. Banker carlson school of management university of minnesota srikant m.
Programming complexity or software complexity is a term that includes many properties of a piece of software, all of which affect internal interactions. It identifies a set of software measures based on correlations published in empirical studies. In software development, complexity refers to the nature and number of interactions between entities within a system, rather than to the complexity of the task that the system performs. Proceedings of the tenth international conference on information systemsdecember 1989 pages 247255.
Reliability, availability, and maintainability ram are three system attributes that are of tremendous interest to systems engineers, logisticians, and users. This metric is a modern software sizing algorithm that parses source code and breaks it down into micro functions. Chug, application of evolutionary algorithms for software maintainability prediction using objectoriented metric, in 8th int. The cyclomatic complexity is more in the classesmethods where there are a lot of conditional operators e. Software maintainability is defined as the degree to which an application is understood, repaired, or enhanced. With multiple system interfaces and complex requirements, the complexity of software systems sometimes grows beyond control, rendering applications and portfolios overly costly to maintain and risky to enhance. The mccabe complexity is one of the more widelyaccepted software metrics, it is intended to be. Developing maintainable software software sustainability. In 24, proposed model considered the different design characteristics and this model pointed out that maintainability is a measure of software characteristics as source. It differs from hardware reliability in that it reflects the design. The complexity is one of the major factors to control the maintainability of software, as more complex software is difficult to edit and test resulting low software quality 3, 4. Software design for maintainability establish design criteria for maintainable software products to increase system availability and decrease overall development and operating costs benefits by designing software products that are maintainable we can update and enhance fielded software much faster and at lower cost.
Comparative study of the software metrics for the complexity and. For every technical debt issue we identify during our 10point inspection, we estimate a rough time it would t. The cyclomatic complexity also affects other software metrics, like code maintainability index. For example, in visual studio, it rely on cyclomatic complexity, depth of inheritance, class coupling and lines of code. In 24, proposed model considered the different design characteristics and this model pointed out that maintainability is a measure of. Code metrics data can be generated for an entire solution or a single. The maintainability index is calculated with certain formulae from linesofcode measures, mccabe measures and halstead complexity measures.
The quality checks and software metrics produced by imagix 4d enable you to identify potential problems during the development and testing of your source code. Maintainability and flexibility at the software level are of predominant importance to drive innovation at the business process level. Measures of software complexity have been developed since the 1970s in an attempt to quantify the internal working of a software system rather than rely on a software developers subjective opinion. In general any software development manager is familiar with this definition of effort as it applies to creating software. By identifying and correcting the problem areas earlier, youre able to improve the security, reliability, and maintainability of your software. Because of increases in the size and complexity of software products, software maintenance tasks have become increasingly more difficult. It is costeffective for software practitioners to monitor and control quality of software systems from the early phases of development. This paper examines the relationships between software complexity and software maintainability in commercial software environments. How to effectively define and measure maintainability. Volume hv metric 2, the cyclomatic complexity cc 3 metric, the average number of lines of code. The idea of linking software complexity to the maintainability of the software has. Software maintenance is a phase in the software development cycle that starts after the customer has received the product. The cyclomatic complexity vg has been introduced by thomas mccabe in 1976.
The maintainability is the major concerns discussed in this paper. Assessing and modeling the effects of design and coding factors on software system maintainability can help provide heuristics to human designers and programmers to reduce maintenance costs and improve quality. The maintainability index is calculated as a factored formula consisting of sloc source lines of code, cyclomatic complexity and halstead volume. Software maintainability 3, is the degree to which characteristics that hamper software maintenance are present and determined by software complexity. Bioinspired information and communications technologies, 2014. Reliability, availability, and maintainability sebok. Introduction software maintainability is the degree to which characteristics that impede software maintenance are present. Regression testing has been widely used during software evolution to ensure that software changes do not bring new regression faults. Technical debt haunts developers and the longer it takes, the more interest rates accrue over this debt. Comparative study of the factors that affect maintainability.