Estimation Design Rework Efforts in the Early Phase of Design and Development Panumas Arundachawat, Rajkumar Roy and Ahmed Al-Ashaab Decision Engineering Centre, Cranfield University UK Abstract. A design rework efforts estimation (DREE) framework is developed in order to identify design rework efforts in the early phase of product design and development. An automotive water pump is used as a case study in this paper. Dependency among components, which are assesed numerically by Analytical Hierarchy Process (AHP), is a key driver on design rework efforts estimation. And then, Work transfer matrix method (WTM) is a mean to estimate design rework efforts. Results based on worst case scenario were validated with experts from an engine manufacturer. Keywords. Design rework efforts, Estimation, Concurrent Engineering, Functional Analysis 1 Introduction Concurrent Engineering (CE) approach is a well known best practice to reduce development cost and lead time now a day. However, it is necessary to understand the characteristics of design rework efforts in order to fully enhance the benefits of CE design approach. This issue has a strong link to cost of design and development project, because it is always viewed as inherent within cost incurred in a design phase. Design efforts are realised as efforts of which considered as time to accomplish a design task by one person (person-month, person-hour), while design rework efforts is define as unnecessary iterations which are the results of design error or design failure due to neglect something previously known or lack of knowledge as discussed in [1]. The repetition efforts spent on requirement changes is considered as out of scope of this paper, because it behave like non-linear phenomena. The aim of this paper is developing a methodology to estimate design rework efforts due to components dependency within a considered product. In this paper, an automotive water pump is used as a case study. All components in a product are assumed to conduct concurrently design until sign off for manufacturing [2]. Design rework efforts are estimated after design validation and verification (V&V) phase finish. Design issues are obviously captured during design V&V, after that analysis will take actions to resolve problems and efforts in this stage is called design rework efforts in this paper. Dependencies among components are the key to achieve design rework efforts estimation, and this framework helps design team to address components which , J. Pokojski et al. (eds.), New World Situation: New Directions in Concurrent Engineering, DOI: 10.1007/978-0-85729-024-3_61, Ó Springer-Verlag London Limited 2010 593