It is intended for routine design situations. It has been tried on mechanical, electrical and civil engineering tasks. Routine design means that everything about the design process, including the knowledge needed, must be known in advance. As the knowledge represents routine problem-solving then we would expect it to be highly compiled. They each represent a subproblem, solving it by plan selection and execution.
Plans are precompiled sequences of actions intended to provide the design for a subproblem.
A Plan provides ordering of design activity and a subproblem decomposition. Plans also provide the basis for solution recomposition. A Sponsor evaluates the suitability of a plan for use in a particular situation, while a Selector picks a suitable Plan. Steps represent the building blocks of the design process, providing a value for an attribute of the design. This is done using calculation or decision, or by selection using pattern matching.