1 Copyright © 2013 by ASME Proceedings of the ASME 2013 International Mechanical Engineering Congress & Exposition IMECE2013 November 15-21, 2013, San Diego, California, USA IMECE2013-63624 SET-BASED CONCURRENT ENGINEERING FOR PRESERVING DESIGN BANDWIDTH IN PRODUCT AND MANUFACTURING SYSTEM PLATFORMS Marcel T. Michaelis, Christoffer Levandowski and Hans Johannesson Chalmers University of Technology, Wingquist Laboratory, Department of Product and Production Development, Gothenburg, Sweden ABSTRACT Assembling products to order or applying straightforward configuration, such as scaling, allow the reuse of ready- designed physical components in high volumes. However, not all companies can exploit economies of scale in this way. They are burdened with additional design work, as requirements on functionality and performance differ among product variants or change over time. Such companies need artifact models and engineering processes that help them manage and develop for variety. Set-based concurrent engineering has been proposed for dealing with a variety of concepts during development that lead to a single product while storing knowledge gained. This paper adapts this thinking to the preparation and use of product and manufacturing system platforms. Here, the output is not a single product. Rather, a set of design solutions for products and manufacturing systems is designed that delivers flexibility in functionality and performance. In this paper, we call this built-in flexibility design bandwidth. The paper builds on an integrated artifact model for products and manufacturing systems. The model captures the rationale behind existing designs with their functionality. Here it is combined with principles of set-based concurrent engineering to outline a process for its preparation and use in cases of insufficient bandwidth that require additional designing. The preparation and use are illustrated by applying the model to an example where bandwidth is expanded and preserved. INTRODUCTION In competitive markets, companies try to appeal to a range of customers by providing customized functionality and performance. Platforms are proposed as an approach to dealing with the resulting variety while achieving commonality in products and manufacturing [1, 2]. These platform approaches often assume mature designs and unchanging manufacturing processes. However, if required functionality and performance change over time, the product design changes and with it the manufacturing system. To avoid the laborious task of repeated platform design, platforms must be prepared with flexibility and maintained for continual use [3]. This leads to platform lifecycles that are separate from the lifecycles of the products and of the manufacturing system. [4]. At the same time, this platform management needs to be supported by suitable artifact models and suitable processes. Two different modes of use can be identified. In the first one, the product and manufacturing platform are flexible enough to accommodate a certain change, and all information required for configuration is available in a model that allows platform execution (Mode I). In the second mode, the focus of this paper, additional design work is required to expand and preserve the design bandwidth (Mode II). Modeling for Changing Product Requirements Addressing the challenge of changing requirements on functionality and performance over time, artifact models have been proposed to help companies manage and develop for variety. Ahmad et al. [5] devised a model that can be used to assess the impact of changes introduced to products. It models the requirements, functions, components, and the detailed design process but does not explicitly address the manufacturing system. AlGeddawy and ElMaraghy [6] propose branching diagrams that allow tracing the historical co- development of products and manufacturing systems and predicting and synthesizing future configurations. They map product features to machine capability or, alternatively, to functionality in order to optimize modularity [7].