Start Technical Development; Preliminary Design and Review
The Technical Development Process (often called the Design, Build, and Test Process), as shown in Figure 8-1, proceeds in a counterclockwise direction through eleven phases. In this chapter we are concerned with the shaded topdown design phases on the left-hand side of Figure 8-1. After Fonming the Venture Team, conducting a QFD study, and developing the Product Design Specification, top-down design proceeds through System Architecture, Subsystem Design, and Part Design and ends with Internal Design Review. In Chapter 9, we will complete Technical Development by completing the build and test phases shown on the right-hand side of Figure 8-1.
From Figure 8-1 and from the description in this chapter, it may appear that the Technical Development Process is a one-pass linear process with no backward loops or repetitions. Nothing could be further from the truth. To make the process easier to understand and comprehend, we have drawn and explained it in a linear fashion. However, in the real world there are normally several iterations of the process, with considerable doubling back within an iteration. During each design, build, and test iteration, we also normally considering several alternative designs.
Specifically, once the developer has framed the design problem by preparing the Product Design Specification, the first step in the design phase is to generate several alternative designs. In an early iteration, the purpose of the alternative designs may be to explore the relationship between design parameters and specific customer needs. In a later iteration, the purpose of the alternative designs may be to refine an established concept.
In the build phase, the developer builds working models of the design alter-