Simplifying Iterations in Cross-Functional Design Decision Making

In this paper, we consider the cross-functional design decision making process and discuss how sequential decision making leads to a degradation in design quality even when downstream design tasks are not rendered infeasible by preceding upstream decisions. We focus on the problem of simplifying the design iterations required to address this quality loss. Two properties, called sequence invariance and task invariance, are introduced to help reduce the complexity of subsequent design iterations. We also discuss how these properties may be used by designers in situations where mathematical descriptions of the design performance characteristics are unavailable. We illustrate the utility of these properties by showing their applicability to the design of catalytic converter diagnostic systems at a major U.S. automotive firm.