In configuration management, a baseline is an agreed description of the attributes of a product, at a point in time, which serves as a basis for defining change. A change is a movement from this baseline state to a next state. The identification of significant changes from the baseline state is the central purpose of baseline identification.
Typically, significant states are those that receive a formal approval status, either explicitly or implicitly. An approval status may be attributed to individual items, when a prior definition for that status has been established by project leaders, or signified by mere association to a particular established baseline. Nevertheless, this approval status is usually recognized publicly. A baseline may be established for the singular purpose of marking an approved configuration item, e.g. a project plan that has been signed off for execution. Associating multiple configuration items to such a baseline indicates those items as also being approved. Baselines may also be used to mark milestones. A baseline may refer to a single work product, or a set of work products that can be used as a logical basis for comparison.
Most baselines are established at a fixed point in time Some examples include:
- Functional baseline: initial specifications established; contract, et cetera
- Allocated baseline: state of work products after requirements are approved
- Developmental baseline: state of work products amid development
- Product baseline: contains the releasable contents of the project
- Others, based upon proprietary business practices
Application
Though common in software revision control systems as labels' or tags, the existence of baselines is found in several other technology-related domains. Baselines can be found in UML modeling systems and business rule management systems, among others.
In addition to the field of hardware and software engineering, baselines can be found in medicine (e.g. monitoring health progress), politics (e.g. statistics), physics and chemistry (e.g. observations and changes), finance (e.g. budgeting), and others.
Baselining configuration items
In the process of performing configuration management, configuration items (or work products) may be assigned a baseline so as to establish them as having a certain status. In this sense, to baseline a work product may require certain change(s) to the work product to ensure it conforms to the characteristics associated with the baseline referenced. This varies upon context, but in many cases this requires that the work product is "reset" to an initial (possibly inherently approved) state from which work may proceed.
Baseline control
In many environments, baselines are controlled such that certain subsequent activities against work products in that baseline are either prohibited or permitted. These activities are selected and controlled, and again, depending upon the configuration management system, are also monitored. Consequently, baselines are ordinarily subjected to configuration management audits. Configuration audits may include an examination of specific actions performed against the baseline, identification of individuals involved in any action, an evaluation of change within the baseline, (re-)certification for approval, accounting, metric collection, comparison to another baseline, or all of these.
See also
- Software configuration management
- Systems development life cycle
- Traceability matrix