No abstract

Customer requirements provide objectives and constraints for all phases of the product development process. For complex system products with a high degree of customization, it is no mean task to ensure that the right persons at the right time have ready access to the selected requirement specifications that they should adhere to and strive to satisfy. In the present work a systematic sequence of development phases associated with computer implemented information structures for requirements, functions and systems have been studied at three companies with widely different products and business scenarios. Although individual adaptations are required, the overall processes for requirement decomposition and propagation appear surprisingly similar. To fully exploit the potential of such information systems, many companies would benefit from also including knowledge structures in their product models. Fundamental product and process knowledge often evolves slowly over time, can be gradually upgraded and be reused many times. It also constitutes one of the company’s most valuable assets and should be carefully maintained and enhanced. In the work presented here a few different approaches to integrating knowledge structures into the total product information structure have been developed and exemplified for the three companies studied.

Choosing methods and tools to automate engineering design tasks has farreaching implications. A system that is first established for a limited task may later require being scaled up and maintained for many years of operational life. As the system grows, the company’s reliance on the system increases and the need for a stable platform to start from becomes critical. The system must be tailored to the specific design process and knowledge structure at hand. The purpose of this work is to present a structured methodology to classify design task(s) and to give guidelines for how this definition should be linked to suitable solution strategies and computerised tools.

In order to place sensors or electronics in very high temperature environments, new materials and methods for interconnection are required. A comparative study between different electrical interconnection methods for very high operation temperatures (500°C -800°C) is presented. Thermo-mechanical simulations and characterization of samples of the interconnection types during high temperature exposure are presented.The results of the thermo-mechanical simulations showed that stresses are low in a connection system based on liquid interconnection. This system, however, proved to be difficult to realize due to problems with oxides and sealing of the metallic liquid. Modeling of an interconnection based purely on mechanical pressure without any solder or metallic bond showed high stress. This was also confirmed during high temperature exposure where the connection failed.High stress was also predicted for an interconnection based on nano-Ag paste. The high temperature tests, however, showed promising results at 800°C for over 100 hours.