Accounting for the Duration of Analyses in Design Process Decisions

Although the design phase can account for a sizable amount of the resources consumed during the product realization process, the time and costs associated with the design process are often neglected when making design decisions. To investigate this issue, we define a process-centric decision model in which the design-phase consumption of resources, such as time and money, is explicitly modeled. While it is clear that the utility of a design is almost always directly impacted by the monetary costs of the design process, our decision model also accounts for the fact that the profit earned by a product depends strongly on its launch date. The decision model allows us thus to consider the trade-off between the time necessary for analysis and the improvement in product quality that results from the analysis. The decision model is sufficiently generic that almost any set of beliefs about the alternatives or analyses, as well as any utility-based preference structure can be modeled. To illustrate the usefulness of the model, it was solved quantitatively for two different design scenarios. The results indicate that designers should consider the duration as well as the monetary cost of analyses; depending on the cost-benefit trade-offs, it may be best to perform analyses sequentially, in parallel, or not at all.