Quality gate
A Quality Gate is a special milestone in a software project. Quality Gates are located before a phase that is strongly dependent on the outcome of a previous phase. They are especially useful between phases in which breaches in disciplines must be overcome. Such a breach typically occurs, for example, when embedded software must be transferred to a hardware chip. Quality Gates are more general than Milestones; Quality Gates can be used in larger set of more or less similar projects, whereas milestones must be defined for each project from scratch.
Each Quality Gate includes a check of documents relevant to the previous phase. Unlike a software review, this check is only formal; no deep check on the contents of applicable documents is conducted in a Quality Gate. A Quality Gate demands a set of documents and includes special requirements on these documents, both of which are detailed in a checklist. The check itself is performed in a session with decision makers and domain experts. Depending on their decision, the project can be cancelled, put on hold, or approved to proceed normally.
The term 'Quality Gate' is not used consistently and can be applied to project management, quality management, risk management, or any combination of these three management disciplines.
The term Quality Gate can be found in different software process models, e.g. the V-Modell XT of the German federal administration. A similar concept can be found in Cooper's Stage-gate model, which, in contrast to the V-Modell XT, is not limited to the domain of software development. It can, moreover, be used for almost any type of new product development. The Stage-gate model can also be used to manage multiple projects, in order to identify the most promising projects and to cancel the risky projects. The goal is to concentrate resources on the more promising projects.