This paper looks at the product development process as an exercise in risk reduction and performs a critical analysis of how gas turbine engine manufacturers weigh the competing risks associated with on-time delivery, product quality, and development costs. Three frameworks are used to focus the analysis: • Iteration by using multiple attempts to converge to an acceptable solution. • Maintaining options in development, and delaying convergence to a single design. • Improving the organization’s predictive capability prior to committing to a particular set of performance goals, designs, or technologies for a product. This is explored from the perspective of “technology readiness”. For six gas turbine engine development programs, case studies were performed to assess the effectiveness of the product development process by measuring how well the engine met its guaranteed level of fuel consumption. For each development program, performance against guarantees was compared against technology readiness levels (TRL) at program launch when performance was guaranteed by contract to customers, and against the degree of flexibility provided to designers to react once performance shortfalls were known. Decomposition of the engine system into sub-systems was necessary to specifically define TRL, parallel efforts, and iteration. Risk strategies were compared in light of the time sensitivity of the quality of information, the cost of engineering changes, contractual penalties, and lead times associated with implementing improvements.
Modeling and managing engineering changes in a complex product development process
