Abstract: A directed heuristic search (DHS) has been developed for an optimization design system. The DHS an optimization simulation system has been developed. The DHS directs a design optimization process that implements a user's selections and directions, the order and directions in which the search for an optimal design is to be conducted, and how the search is to sequence through potential design solutions. In addition, DHS is tractable, in that it records a log of the sequence of design solutions that were evaluated during a particular design optimization search. The user may review this search log, to understand how and why the DHS made design optimization decisions. The user may change search parameter settings in a user defined dependency to change future search patterns for optimal designs.