Commercial gas turbine engine platform strategy and design

Abstract

Product development challenges companies to produce designs that meet customer requirements yet, that are within their technological and financial means to do so. The proliferation of customized or unique designs may tax the resources of a firm if product variety cannot be achieved in a cost-effective manner. A product platform strategy allows a set of core elements or subsystems to be shared across all or part of a company's product portfolio, while design flexibility allows differentiated functions to satisfy specific customer needs. A framework for identifying potential platform elements from among key system design variables is provided. This framework supports the hypothesis that system design variables with low normalized coupling and low normalized variation across a set of conceptual product designs should be considered as potential platform elements. A system level approach for identifying the coupling and variation of these elements is facilitated through the formulation and use of a modified quality function deployment (QFD) mapping procedure. Normalized coupling is quantified as the relative importance of relationships between stakeholder needs, system requirements and system design variables, divided by a ranking of the difficulty in their achievement. Normalized variation of system design variables from a sample of parameter data is calculated as the standard deviation divided by the mean. The proposed framework and hypothesis is validated with a case study of the Pratt & Whitney PW4000 family of commercial gas turbine engines where predicted platform elements were consistent with actual design choices.