When designing a home, architects represent it in many ways to fully understand and convey its essence to builders, buyers of materials, and home buyers: elevations, floor plans, framing, trusses, electrical routing, plumbing routing, concrete shape, door and window framing details, and other points of view. The same is true of software design.
A complete software design includes at least:
- Packaging. Often drawn as a hierarchy chart, this captures "what is part of what?" It often implies data visibility. It also shows encapsulation, such as data and functions within objects.
- Needs hierarchy. This captures "who needs whom?" Drawn as a network of components, arrows indicate which components need something. The needs might be data, logic, or any other information.
- Invocation. This captures "who invokes whom?" Drawn as a network of components, arrows indicate which components "call," "interrupt," or "send messages to" others.
- Processes. Sets of components are packaged together as asynchronous processes. These are copies of components that are running simultaneously with other processes. Zero, one, or more copies may exist at one time. This should also specify conditions that cause a process to be created, executed, stopped, and destroyed.
Reference:
Witt, B., Baker, F., and Merritt, E., Software Architecture and Design, New York: Van Nostrand Reinhold, 1994.
