Platform-Based Design - Design Rationale Aspects within the Configurable Component Concept

Licentiatavhandling, 2009

Competition, emanating from globalization and the continuing evolution in supplier chains, especially within the automotive industry, creates pressure on every phase of a design´s lifecycle to be more efficient. Requirements, which at least are perceived as conflicting, on one hand a low product price achieved by high volumes and economy of scale, and on the other hand the customers´ whish of individualized products, push for new approaches. Masscustomization has been one approach to meet the challenge. The actors´improved ability to deliver new products to the market has shortened the window in which products are competitive. This puts a pressure on the actors to improve their responsiveness. The challenges drive for further increases in efficiency and ability to customize while being profitable. One solution is reuse in its widest meaning, e.g. parts, concepts, production processes and ideas, which can be implemented with platform-based design. To deal with: concurrency in an efficient way, derivate designs based on platforms, and variant rich designs demands for new ways to describe the designs. The introduction of the Configurable Component Concept is intended to support concurrent, complex, variant rich system design in an efficient way, in all lifecycle phases. Re-use can benefit in various ways from knowledge rich design descriptions when information, why the design is as it is, is explicitly given. With knowledge of the reasoning behind the design and what consideration resulted in the design, what is referred to as the why knowledge, it is more likely that the design can be used and re-used correctly. The why information can be perceived as a bridge, between distances in time and space. Bridging distances in time means knowing how to use the design properly and also know how to modify it without accidently loosing wanted behavior or more fundamentally, to dare to make any changes at all instead of re-making the complete design. Bridging distances in space deals with uses in multiple contexts, i.e. use it in another design than the primary intended one, as well as concurrent activities where multiple organizations are involved simultaneously. This licentiate thesis presents how the function-means tree method is integrated with the configurable component concept to act as a design rationale. This includes: an extended function-means tree method to handle design bandwidth, a more transparent and explicit constraint handling, and design decisions that together form an explicit function-means tree instance. The function-means tree is also adapted to work as an integrated element within a configurable component, representing any (sub-) system design, in contrast to the traditional representation where it represents a complete design.