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Today the lack of deliveries from suppliers to automotive OEMs in early phases of software development cause a number of problems such as misinterpreted requirements and difficulties in keeping deadlines. We have identified use cases as a means to communicate and visualize requirements. A well defined standard is needed to enable communication between different organizations.In this paper we propose a two level use case standard for embedded systems. The standard consists of a template and guidelines specifying how to write consistent and unambiguous use cases while capturing the necessary requirements.

This paper presents an empirical quality assessment of use cases with the purpose to provide defect data from industry. In the assessment, twelve criteria, based on earlier research, were applied to 43 use cases from Volvo Car Corporation developed according to current practice. The collected defect data were statistically analyzed to determine significant intensity differences and to establish a partial order between the defects types based on their intensity. In addition, a qualitative assessment was made to assess the effect of remaining defects on the established order. The study shows that the defect types with the highest defect intensity are Missing element and Incorrect linguistics. Further, the established defect order is the basis for a comparison between the criteria used and earlier research on guidelines and checklists for use case authoring, resulting in improvement propositions.

There is a lack of early project control when automotive software is developed by external suppliers. This paper proposes a process improvement that targets early deliverables from suppliers as a means to improve project control. An addition to the existing automotive process employing a two-level use case approach is presented. In an example study involving Volvo 3P we show that the process improvements are applicable in real industrial development processes and that use cases are suitable for automotive requirements communication. The example also showed that use cases can be employed at the level of detail necessary to describe embedded systems.