Definition av acceptanskriterier och utveckling av uppföljningsmetod för drivlinestyrsystem på Scania

Abstract: The division NE (Powertrain Control System) at Scania develops powertrain control systems and the group NEVT (Test coordination and support) within NE is responsible for the follow-up and quality checking of these systems. To validate the systems, these are test-driven in trucks and buses, both in field tests by external customers and internally, by Scania-employed drivers. To assure a high quality, several demands and one specific criteria must be met for acceptance. The current acceptance criteria measures driving distance per fault code (km/Dtc) but is set quite high and is difficult to pass. The follow-up of the acceptance criteria is done manually and it is also hard to get a clear overview of different projects and be able to measure and compare them. Therefore, there is a need for new acceptance criteria and new means for analysis and follow-up of project results and criteria. The aim of this thesis is to evaluate and do a follow-up of the current acceptance criterion. Furthermore, it aims to generate propositions for new acceptance criteria which can assure a quality assured follow-up of the powertrain control systems. In addition, a method for describing a systematic, structured work flow for following up future acceptance criteria is to be developed. A literature study was conducted to gather general information concerning software development. However, information on acceptance testing for powertrain control systems is scarce and most of the data needed for the research was therefore gathered internally via interviews at Scania Södertälje. The data was then analyzed and developed into primary results. Following the data analysis, the primary results were presented in a workshop for feedback. The primary results were then evaluated and refined into final results. Lastly, the final results were put through a pilot project at Scania to verify their level of accuracy and to assure that the developed method for follow-up was working properly. The final results include: Two new acceptance criteria concerning fault codes, based on statistics from the current criterion as well as a new way of counting fault codes and new acceptance levels for the criterion. An acceptance criterion for drivability, including a minimum value and a lowest acceptable value for drivability scores, measured through the use of subjective scales. A method for follow-up and analysis of the acceptance criteria.