Some terms which are used in the following sections are defined below to facilitate understanding:
program system
A program system is a logical grouping of software components, for example the components of a software project.
component
A component contains data which belongs together. One example of a component is a library member that contains text.
derived component
A derived component is one which is generated from other components through automatic processing, for example a compilation listing.
source (component)
A source component is one which was not generated from any other component. As a rule, sources are components which are developed manually, for example the source texts of programs, macros or documents.
current
A program system may be referred to as being “current” if it includes all the recent updates of the sources from which it is generated.
dependency
A component is dependent on the components from which it is derived.