Introducing Flexible Quantity Contracts into Distributed SoC and Embedded System Design Processes ∗ Judita Kruse, Clive Thomsen, Rolf Ernst Institute of Computer and Communication Network Engineering kruse|thomsen|ernst@ida.ing.tu-bs.de Thomas Volling, Thomas Spengler Institute for Economics and Business Administration t.volling|t.spengler@tu-bs.de Technical University of Braunschweig, D-38106 Braunschweig/Germany Abstract Increasing design complexity eventually leads to a de- sign process that is distributed over several companies. This is already found in the automotive industry but SoC de- sign appears to move in the same direction. Design pro- cesses for complex systems are iterative, but iteration hardly reaches beyond company borders. Iterations require avail- ability of preliminary design data and estimations, but due to cost and liability issues suppliers often hesitate to pro- vide such preliminary data. Moreover, companies are rarely able to judge the accuracy and precision of externally es- timated data. So, the systems integrator experiences in- creased design risk. Particular mechanisms are needed to ensure, that the integrated system will meet the overall re- quirements even if part of the early estimations are wrong or imprecise. Based on work in supply chain management, we propose an inter-company design process that is based on formal techniques from real-time systems engineering and so called flexible quantity contracts. In this process, formal techniques control design risk and flexible contracts regulate cooperation and cost distribution. The process ef- fectively delays the design freeze point beyond the contract conclusion to enable design iterations. We explain the pro- cess and give an example. 1. Introduction Efficient design processes and new strategies are needed to meet the challenges of the increasing complexity of cur- rent and future embedded system and SoC designs. In- dustries like automotive engineering and space applications have established sophisticated supplier-integrator chains. We expect that the semiconductor SoC design will follow the same path in SoC development. The success of IP ∗ This work is supported by a grant from EADS and from the EU in the SpeAC project (MEDEA+ A508). providers such as ARM and their frameworks for inter- company exchange and interoperability of documents and tools [3] are clear indicators Such supply chains turn out to be the first step towards a distributed design process. Today we already find dis- tributed design processes in automotive engineering and space applications, where software plays an important role. Distributed design processes are spread over several compa- nies and cover the whole design flow from subcomponents to the integration of the overall system. Increasing SoC complexity, multiple layers of hard- ware dependent software, application programmer inter- faces, and third party software libraries give raise to fur- ther design process distribution over a heterogeneous set of players that follow divergent business goals. They must be coordinated via engineering and business mechanisms. It is about time for systematic approaches to that issue that put these mechanisms into context. Especially in complex product development implemen- tation and integration are done in the late phases of classi- cal design flows (e.g. specified for ESA projects by ECSS standard ’System Engineering’ [8]). Hence accurate as- sertions about design data and objective requirements are late as well. But contracting based on design specifications containing requirements is done at the beginning of a new design. Therefore integrator and suppliers estimate their needs conservatively leading to increased cost and subop- timal products. One key problem in distributed design processes is to reach true collaborative inter-company developments, while keeping corporate know-how proprietary at the same time. The approach in this paper was motivated by the SpeAC project in which a large space systems company, EADS Astrium, develops an inter-company design flow with two suppliers and applies it to a concrete satellite hard- ware/software subsystem development as a demonstrator. As a prerequisite, design data are shared between the com- panies using restricted access mechanisms to protect IP and management internals. 1530-1591/05 $20.00 © 2005 IEEE