Representing Systems With Context Diagrams

by Kenneth A. Kozar

Spring 1997


A context diagram is the highest level graphic representation of a system. It shows data along with the data's sources and destinations to and from the system. These sources and destinations are called external entities, since they are external to the system boundary. In some cases, the diagram also may show data flow between external entities, especially if a system boundary is unclear to the analyst.

See the context diagram for a system for building systems. The squares are external entities. The letters in the lower right hand corners of the squares are short identifiers. The diagonal lines in the external entity corners indicate that the external entity is duplicated somewhere on the page.

You may want to see another context diagram in a University setting: