Interpretation Discrepancies of SysML State Machine: An Initial Investigation

Model-Based Systems Engineering (MBSE) is expected to improve communication and consistency in system development over document-based approaches. As systems become more complex, modeling languages increase the information content of their semantics to simplify modeling construction and visualization. We hypothesize in this paper that such increase in the complexity of the semantics may be detrimental to the MBSE objectives of facilitating communication and consistency. We present the results of an initial survey in which we asked systems engineers individually to interpret the behavior captured by several models in the form of Systems Modeling Language (SysML) state machines. Significant discrepancies in their answers were found. In addition, we present a qualitative assessment of the potential implications of such interpretation discrepancies for system development, which include need for rework, modeling gaps, inefficient solutions, and solutions that are not fit for purpose.