The proposed OTX format represents a standardized, tester-independent, XML-based data exchange format for the documentation and formal description of diagnostic test sequences. An overview how OTX fits into the structure of existing diagnostic ISO standards is given in Figure 1. Please note that although this overview is depicting OTX in the context of ISO 22900 (MVCI) and ISO 22901 (ODX) standards, OTX is by no means designed to be used only in conjunction with these standards. The use of any other equivalent symbolic data description is also supported. It is a design goal of OTX that the OTX data model can be used within any system context.