In computer science and

software engineering Software engineering is a systematic engineering approach to software development. A software engineer is a person who applies the principles of software engineering to design, develop, maintain, test, and evaluate computer software. The term '' ...

, reusability is the use of existing ''assets'' in some form within the software product development process; these ''assets'' are products and by-products of the software development life cycle and include code, software components, test suites, designs and documentation. The opposite concept of ''reusability'' is leverage, which modifies existing assets as needed to meet specific system requirements. Because reuse implies the creation of a , it is preferred over leverage. Subroutines or functions are the simplest form of reuse. A chunk of code is regularly organized using

modules Broadly speaking, modularity is the degree to which a system's components may be separated and recombined, often with the benefit of flexibility and variety in use. The concept of modularity is used primarily to reduce complexity by breaking a sy ...

namespace In computing, a namespace is a set of signs (''names'') that are used to identify and refer to objects of various kinds. A namespace ensures that all of a given set of objects have unique names so that they can be easily identified. Namespaces ...

s into layers. Proponents claim that

object Object may refer to: General meanings * Object (philosophy), a thing, being, or concept ** Object (abstract), an object which does not exist at any particular time or place ** Physical object, an identifiable collection of matter * Goal, an ai ...

s and

software component Component-based software engineering (CBSE), also called component-based development (CBD), is a branch of software engineering that emphasizes the separation of concerns with respect to the wide-ranging functionality available throughout a giv ...

s offer a more advanced form of reusability, although it has been tough to objectively measure and define levels or scores of reusability. The ability to reuse relies in an essential way on the ability to build larger things from smaller parts, and being able to identify commonality among those parts. Reusability is often a required characteristic of platform software. Reusability brings several aspects to

software development Software development is the process of conceiving, specifying, designing, programming, documenting, testing, and bug fixing involved in creating and maintaining applications, frameworks, or other software components. Software development invol ...

that do not need to be considered when reusability is not required. Reusability implies some explicit management of build,

packaging Packaging is the science, art and technology of enclosing or protecting products for distribution, storage, sale, and use. Packaging also refers to the process of designing, evaluating, and producing packages. Packaging can be described as a co ...

distribution Distribution may refer to: Mathematics *Distribution (mathematics), generalized functions used to formulate solutions of partial differential equations *Probability distribution, the probability of a particular value or value range of a varia ...

, installation,

configuration Configuration or configurations may refer to: Computing * Computer configuration or system configuration * Configuration file, a software file used to configure the initial settings for a computer program * Configurator, also known as choice board ...

, deployment,

maintenance Maintenance may refer to: Biological science * Maintenance of an organism * Maintenance respiration Non-technical maintenance * Alimony, also called ''maintenance'' in British English * Champerty and maintenance, two related legal doctri ...

and

upgrade Upgrading is the process of replacing a product with a newer version of the same product. In computing and consumer electronics an upgrade is generally a replacement of hardware, software or firmware with a newer or better version, in order ...

issues. If these issues are not considered, software may appear to be reusable from

design A design is a plan or specification for the construction of an object or system or for the implementation of an activity or process or the result of that plan or specification in the form of a prototype, product, or process. The verb ''to design'' ...

point of view, but will not be reused in practice. Software reusability more specifically refers to design features of a software element (or collection of software elements) that enhance its suitability for reuse. Many reuse design principles were developed at the WISR workshops. Candidate design features for software reuse include: * Adaptable * Brief: small size * Consistency * Correctness *

Extensibility Extensibility is a software engineering and systems design principle that provides for future growth. Extensibility is a measure of the ability to extend a system and the level of effort required to implement the extension. Extensions can be th ...

* Fast * Flexible *

Generic Generic or generics may refer to: In business * Generic term, a common name used for a range or class of similar things not protected by trademark * Generic brand, a brand for a product that does not have an associated brand or trademark, other ...

* Localization of volatile ( changeable) design assumptions (

David Parnas David Lorge Parnas (born February 10, 1941) is a Canadian early pioneer of software engineering, who developed the concept of information hiding in modular programming, which is an important element of object-oriented programming today. He is ...

) *

Modularity Broadly speaking, modularity is the degree to which a system's components may be separated and recombined, often with the benefit of flexibility and variety in use. The concept of modularity is used primarily to reduce complexity by breaking a sy ...

Orthogonality In mathematics, orthogonality is the generalization of the geometric notion of ''perpendicularity''. By extension, orthogonality is also used to refer to the separation of specific features of a system. The term also has specialized meanings in ...

Parameterization In mathematics, and more specifically in geometry, parametrization (or parameterization; also parameterisation, parametrisation) is the process of finding parametric equations of a curve, a surface, or, more generally, a manifold or a variety, de ...

* Simple: low

complexity Complexity characterises the behaviour of a system or model whose components interact in multiple ways and follow local rules, leading to nonlinearity, randomness, collective dynamics, hierarchy, and emergence. The term is generally used to ch ...

* Stability under changing

requirements In product development and process optimization, a requirement is a singular documented physical or functional need that a particular design, product or process aims to satisfy. It is commonly used in a formal sense in engineering design, includ ...

Consensus has not yet been reached on this list on the relative importance of the entries nor on the issues which make each one important for a particular class of applications.

References

{{Authority control Source code Software quality

See also

References