Proceedings of IDETC/CIE 2005 ASME 2005 International Design Engineering Technical Conferences & Computers and Information in Engineering Conference September 24-28, 2005, Long Beach, California, USA DETC2005-84259 ON PROVIDING FORMAL MANUFACTURABILITY INFORMATION TO UPSTREAM PRODUCT DEVELOPMENT PROCESSES: METHODOLOGY AND CASE STUDY Eliab Z. Opiyo Department of Design and Production Engineering University of Dar es Salaam P. O. Box 35131, Dar es Salaam United Republic of Tanzania ezopiyo@udsm.ac.tz ABSTRACT Process planning is a key product development activity that links design and manufacturing, and is traditionally carried out based on the outcome of the design process. One of the consequences of conducting process planning after design is that the process planning (manufacturability) information needed in the execution of upstream activities is in most cases not available formally. Using informal manufacturability information in the early phases of the product development process can lead to e.g. untrustworthy feasibility study or unnecessary design iterations. As an attempt to solve this problem, a modular procedure for execution of process planning activities is proposed in this paper. It allows for the execution of some of the process planning activities to commence as soon as the details of the order and the requirements for the product are known. The goal is to ensure that formal manufacturability information is available in various stages of the product development process, including to those activities that take place prior to process planning. The new modular process planning procedure has been applied, and it has been found that the design iterations caused by lack of manufacturability information can be avoided. This paper first defines the problem and presents related works. It then introduces the modular process planning procedure, and presents an application case study. KEYWORDS Manufacturability, process planning, design for manufacturability, product development. 1. INTRODUCTION Process planning is an activity that involves preparation of detailed work instructions to machine or assemble parts [Chang (1990); Lee (1999); Chang et al. (1998)]; and it establishes which processes, production machines and parameters should be used. The end products of process planning are chunks of manufacturability information, which includes among other things; a description of the processing parameters and of the sequence of the selected manufacturing or assembly operations. This activity is traditionally carried out based on the design of the product [Figure 1], and it is understood to be the main source of manufacturing information [see e.g. van Houten (1991)]. Ironically, the processes that precede process planning, e.g. the design process (i.e. both conceptual and detail design) also require process planning (manufacturability) 1 information. And even the decision-makers needs manufacturability information in the very early stages of the product development process in order e.g. to decide on whether to accept or reject an order, or to roughly project the product development cost and profit. Many researchers recognize the necessity of availing manufacturability information to the designers early on [see e.g. Arbab (1982); Faux (1986); Boothroyd et. al. (1994); Dixon and Poli (1995); Shah and Mäntylä (1995); Nederbragt et al. (1998); Grayer (1976); Dewhurst and Boothroyd (1989)], and there have been many attempts to deal with the challenge of integrating design and process planning or manufacturing. For example, several methods and tools for cost estimation based on conceptual or final product designs have been developed [Dewhurst and Boothroyd (1989); Ou-Yang and Lin (1997); Winch (1989); Mileham et al. (1993)], and numerous process and set-ups selection methods have been proposed [Boerma and Kals (1988); Harish et al. (2003); Haudrum (1994); Giachetti (1998); Mukherjee and Liu (1997)]. Attempts have also been made to integrate process planning and scheduling [Kim et al. (2003); Kumar and Rajotia (2003)]. The 1 In this article, the phrase ‘process planning information’ is used synonymously with ‘manufacturability information’ and with ‘manufacturing information’. 1 Copyright © 2005 by ASME