This chapter has discussed a number of manufacturing processes, and they were grouped into 8 general divisions. After that examples of templates were given for equation forms corresponding to various manufacturing processes.

After the discussion of the templates, the rules that they could activate were discussed. This discussion included conditions, rules, and results. Theses rules had a simple ‘if-then’ approach. Finally a planning strategy for the rules was presented. The strategy showed how the rule templates would first be used to prune the search tree. After the number of candidate rules was reduced they were examined one at a time until a number of alternative operations were found. Then the least expensive operation was selected. This continued until the process plan was complete, or the planner was forced to backtrack and try a new solution.

A point of interest is that before the planner starts, the design equation is broken down into assemblies, and duplicate parts. At this point the Assembly operators become a valuable reference for separation into subassemblies for manufacturing.

In terms of planning capabilities, it is best to summarize them on an AI basis. First the planner is capable of dealing with non-linear plans where goals (part features) can only be produced in certain sequences. This is done with backtracking. At present the planner will only deal with one goal at once. Therefore there are some problems that it is not capable of solving. The planner is by definition Hierarchical. This is a result of the use of templates to prune the search tree before the rules are applied.

Some aspects of the planner are only discussed in brief, but deserve consideration, such as the use of Meta-goals in the system proposed by Nylund and Novak [1992] for turned parts. Meta-knowledge is also considered in Hummel and Brooks [1988].