The automotive industry is one of the sectors which has been affected significantly by the industrial software revolution during the last few years. Competitive challenges, which are of major relevance for the growing number of software-based automotive innovations, are presented by a dramatic growth in system complexity, rising time and cost pressure, and high quality demands. All these requirements lead to a number of software-related challenges which will be of significant competitive importance for the automotive industry in the future. Asides from the question of whether an automotive company decides to develop software in-house or whether this is carried out by suppliers, every automotive key player has to hold or to build up specific software competencies. The most important competence areas are the software development process, software quality management including supplier cooperation, the overall architecture of the in-vehicle software, as well as the ability to specify, to integrate and to test the system.

Abstract The most important prerequisite for a thorough software test is the determination of relevant test cases. The classification‐tree method suggested in this paper supports the systematic determination and description of test cases. It is based on the idea of partition testing. By means of the classification‐tree method, the input domain of a test object is regarded under various aspects assessed as relevant by the tester. For each aspect, disjoint and complete classifications are formed. Classes resulting from these classifications may be further classified—even recursively. Test cases are formed by combining classes of different classifications. The stepwise partition of the input domain by means of classifications is represented graphically in the form of a tree. This tree is subsequently used to form a combination table in which the test cases are marked. Extensions of the graphical notation and tool support allow the use of the method even for extensive test problems.