The concept behind optimum design is to get the most from an engineering design with the least cost, effort, or materials. The analysis generally starts with a

A. Criterion Function C=C(x,...zn)

Generally there is only one such function and it can represent any or all of the following

1. Cost of manufacturing a product 2. Total weight of a design 3. Power developed by a design 4. Energy absorbed by a design 5. Efficiency of the design

These are some of the factors which the engineer must take into account to get the least or most out of their design with the criterion function. There are other constraints that must be satisfied:

B. Functional Constraints

These are the physical laws which an engineer must follow for a successful design

1. Stress equations 2. Calculations for thrust, lift, drag 3. Deflections 4. Buckling

Functional constraints are factors which engineers have studied in their undergraduate years and dealt with during career.