Beyond Objects: A Software Design Paradigm Based on Process Control

Author: Mary Shaw

Appeared in ACM Software Engineering Notes, Vol 20, No 1, January 1995.

Download the Postscript or PDF


A standard demonstration problem in object-oriented programming is the design of an automobile cruise control. this design exercise demonstrates object-oriented techniques well, but it does not ask whether the object-oriented paradigm is the best one for the task. Here we examine the alternative view that cruise control is essentially a control problem. We present a new software organization paradigm motivated by process control loops. The control view leads us to an architecture that is dominated by analysis of a classical feedback loop rather than by the identification of discrete stateful components to treat as objects. The change in architectural model calls attention to important questions about the cruise control task that aren't addressed in an object-oriented design.

Brought to you by the Composable Software Systems Research Group in the School of Computer Science at Carnegie Mellon University.

[Last modified 11-Feb-1999.
Mail suggestions to the