In software development,
peer review
Peer review is the evaluation of work by one or more people with similar competencies as the producers of the work ( peers). It functions as a form of self-regulation by qualified members of a profession within the relevant field. Peer revie ...
is a type of
software review in which a work product (document, code, or other) is examined by author's colleagues, in order to evaluate the work product's technical content and quality.
Purpose
The purpose of a peer review is to provide "a disciplined engineering practice for detecting and correcting defects in software artifacts, and preventing their leakage into field operations" according to the
Capability Maturity Model.
When performed as part of each
Software development process activity, peer reviews identify problems that can be fixed early in the lifecycle.
That is to say, a peer review that identifies a requirements problem during the
Requirements analysis
In systems engineering and software engineering, requirements analysis focuses on the tasks that determine the needs or conditions to meet the new or altered product or project, taking account of the possibly conflicting requirements of the ...
activity is cheaper and easier to fix than during the
Software architecture
Software architecture is the fundamental structure of a software system and the discipline of creating such structures and systems. Each structure comprises software elements, relations among them, and properties of both elements and relations.
...
or
Software testing activities.
The National Software Quality Experiment, evaluating the effectiveness of peer reviews, finds, "a favorable return on investment for software inspections; savings exceeds costs by 4 to 1". To state it another way, it is four times more costly, on average, to identify and fix a software problem later.
Distinction from other types of software review
Peer reviews are distinct from
management reviews, which are conducted by management representatives rather than by colleagues, and for management and control purposes rather than for technical evaluation. They are also distinct from
software audit reviews, which are conducted by personnel external to the project, to evaluate compliance with specifications, standards, contractual agreements, or other criteria.
Review processes
Peer review processes exist across a spectrum of formality, with relatively unstructured activities such as "buddy checking" towards one end of the spectrum, and more Informal approaches such as
walkthroughs,
technical peer reviews, and
software inspections, at the other. The
IEEE defines formal structures, roles, and processes for each of the last three.
Management representatives are typically not involved in the conduct of a peer review except when included because of specific technical expertise or when the work product under review is a management-level document. This is especially true of line managers of other participants in the review.
Processes for formal peer reviews, such as
software inspections, define specific roles for each participant, quantify stages with entry/exit criteria, capture
software metrics
In software engineering and development, a software metric is a standard of measure of a degree to which a software system or process possesses some property. Even if a metric is not a measurement (metrics are functions, while measurements are t ...
on the peer review process.
"Open source" reviews
In the
free / open source community, something like peer review has taken place in the engineering and evaluation of
computer software
Software is a set of computer programs and associated documentation and data. This is in contrast to hardware, from which the system is built and which actually performs the work.
At the lowest programming level, executable code consists ...
. In this context, the rationale for peer review has its equivalent in
Linus's law, often phrased: "Given enough eyeballs, all bugs are shallow", meaning "If there are enough reviewers, all problems are easy to solve."
Eric S. Raymond has written influentially about peer review in
software development.
[{{cite document, author=Eric S. Raymond, title=The Cathedral and the Bazaar, title-link=The Cathedral and the Bazaar, author-link=Eric S. Raymond]
References
Software review
Peer review