A vital component of computer-aided engineering design is the base program which computes the behavior of an arbitrary design, given a minimal input of both the structural identity and the design parameters. This paper considers the computer-aided design of multifreedom, constrained mechanical systems (realistic machinery). Characteristics of such systems and their computational representation and graphic display output are discussed in terms of an example machine system. An outline of mathematical methods useful for generalized representation is made. Finally an organizational scheme for implementation of a generalized program is briefly discussed. A preliminary program based on these methods is presently under test.