Triform programs
Dan W. Crockett · Communications of the ACM · 1981
The concept that three process functions—initialization, production, and completion—and a separate supervisory control function are sufficient to describe the execution of a program is the basis for Triform Program design. Triform programs are composed of modules arranged in a trifurcate tree structure with each branch devoted to the performance of one and only one of the process functions. The root of the program tree is a control module which supervises process-function execution. Such trifurcate tree structures are shown to be minimum complexity structures.