Beyond Objects: A Software Design Paradigm Based on Process Control

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.