Influence of system architecture changes on organizational work flow and application to Geared turbofan engines

摘要

The design and development of a gas turbine engine for aircraft applications is a highly integrated process, and requires the integration of efforts of large numbers of individuals from many design specialties. If the design process is well defined and the product architecture is stable, the outcome of the process will become highly predictable and repeatable. In the case that there are significant architecture changes due to technology insertion, customer requirements or overall changes in component configuration for performance, this large and integrated design process may become more challenging. Communication of design intent, requirements and predicted performance for all of the components, systems and subsystems must be made without error to all involved in the development of the product. Pratt & Whitney is a large gas turbine engine design company, and has been in the engine business since it's inception in 1925. In 2008, P&W designed, built and flew a large "Geared Turbofan" engine which was a demonstrator for a new product architecture being developed, the first of the new product family being the PWl 524G. This new engine architecture is different from the more traditional turbofan engine architecture in the use of a reduction gear set between the fan and the turbine shaft which drives it. Earlier work in examination of gas turbine engine product-design process interactions has been performed with a traditional high bypass ratio gas turbine engine architecture using the PW4098. Using two test cases, the PW4098 and PW1524G, this work seeks to map the architecture of a gas turbine aero engine in the Design Structure Matrix format, with all major connectivity shown, and then to apply organizational information in the form of Domain Matrix Maps to the physical architectural connectivity to determine which portions of the architecture result in additional or functional group interactions. The determination of the architecture driven changes in the number of functional group interactions is made first, and then isolation of "novel" functional group interactions is made with the original architecture serving as the baseline for organizational interaction. Analysis of these results is then performed to examine the potential organizational impact of moving from traditional turbofan architecture to a geared turbofan architecture. The potential impact to the organization in assessed and recommendations are made to minimize the potential impact of the change. The analysis presented shows that the change in engine architecture represents a move to a more distributed and less modular architecture. The DSM shows a 20% increase in density of connectivity between components. From an organizational impact perspective, there is a 30% change overall in the total number of functional group interactions in the integration of the engine. The impact of these changes on particular design functional groups is discussed, and the data suggests that the more distributed architecture of the PW1524G likely will require more system integration effort than the traditional turbofan architecture of the PW4098.