In
engineering
Engineering is the use of scientific principles to design and build machines, structures, and other items, including bridges, tunnels, roads, vehicles, and buildings. The discipline of engineering encompasses a broad range of more speciali ...
, maintainability is the ease with which a product can be maintained to:
* correct defects or their cause,
*
Repair or replace faulty or worn-out components without having to replace still working parts,
* prevent unexpected working conditions,
* maximize a product's useful life,
* maximize efficiency, reliability, and safety,
* meet new
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, inclu ...
,
* make future maintenance easier, or
* cope with a changing environment.
In some cases, maintainability involves a system of
continuous improvement - learning from the past to improve the ability to maintain systems, or improve the reliability of systems based on maintenance experience.
In
telecommunication
Telecommunication is the transmission of information by various types of technologies over wire, radio, optical, or other electromagnetic systems. It has its origin in the desire of humans for communication over a distance greater than that ...
and several other engineering fields, the term maintainability has the following meanings:
* A characteristic of design and installation, expressed as the probability that an item will be retained in or restored to a specified condition within a given period of
time
Time is the continued sequence of existence and event (philosophy), events that occurs in an apparently irreversible process, irreversible succession from the past, through the present, into the future. It is a component quantity of various me ...
, when the
maintenance is performed by prescribed procedures and resources.
* The ease with which maintenance of a
functional unit can be performed by prescribed requirements.
Software engineering
In
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 '' ...
, these activities are known as
software maintenance
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 merely involves fixing defects. H ...
(cf.
ISO/IEC 9126). Closely related concepts in the software engineering domain are evolvability, modifiability,
technical debt, and
code smells.
The maintainability index is calculated with certain formulae from
lines-of-code measures,
McCabe measures and
Halstead complexity measures
Halstead complexity measures are software metrics introduced by Maurice Howard Halstead in 1977 as part of his treatise on establishing an empirical science of software development.
Halstead made the observation that metrics of the software should ...
.
The measurement and tracking of maintainability are intended to help reduce or reverse a system's tendency toward "code entropy" or degraded integrity, and to indicate when it becomes cheaper and/or less risky to rewrite the code than it is to change it.
See also
*
List of system quality attributes
Within systems engineering, quality attributes are realized non-functional requirements used to evaluate the performance of a system. These are sometimes named architecture characteristics, or "ilities" after the suffix many of the words share. ...
*
Maintenance (technical)
The technical meaning of maintenance involves functional checks, servicing, repairing or replacing of necessary devices, equipment, machinery, building infrastructure, and supporting utilities in industrial, business, and residential installa ...
*
Supportability (disambiguation)
*
Serviceability (disambiguation)
*
Software sizing
*
RAMS
*
Throwaway society
References
Further reading
*
*
*
External links
Calculation, Field testing and history of Maintainability Index (MI) (with references)*
{{Software quality
Telecommunications engineering
Design for X
Maintenance
Software quality