Over the past decade, Systems Engineering has switched from document-centric approaches to model-based ones. In this context, Model Based System Engineering (MBSE) and Multidisciplinary Design Analysis and Optimization (MDAO) have emerged as two complementary disciplines. How to combine MBSE and MDAO approaches for the benefits of systems engineers is still an open issue. This paper discusses a case study of coupling MBSE and MDAO. The MBSE part relies on SysML and timed automata, two modeling languages that are supported by the TTool and UPPAAL-SMC tools, respectively. The MDAO part is developed in the context of Open MDAO. The paper uses a drone as a case study and focuses discussion on battery usage. The SysML model of the drone is enhanced with a timed automata model of the battery. The SysML model of the battery is populated with results from MDAO analysis. In this context, combining SysML, UPPAAL-SMC and Open-MDAO offers to improve self-confidence in some values lying in the model, improve self-confidence in the requirements satisfaction, as well as to refine some requirements values with better accuracy.

Over the past two decades, the promoters of Model Based Systems Engineering (MBSE) have encouraged systems engineers to transition from document-centric approaches to model-based ones. Literacy of systems engineers in reading, sharing and elaborating models has therefore become an issue. Whatever the modeling language, elaboration of models is a highly complex intellectual process and SysML is no exception. Feedback from industry practitioners and MBSE lecturers suggests that developers of SysML models often stumble on the same problem: thinking about the system before modeling it in SysML. The authors of this paper propose to ease that elaboration process by using mind maps. With their graphic form and rather flexible way of organizing ideas, mind maps turn out to be a good candidate to help thinking about the system. Unlike approaches that directly switch from mind maps to SysML diagrams dedicated to one specific system, this paper introduces an intermediate step: mind maps first enable elaboration of diagrams patterns. The latter may in turn be instantiated on one or several systems. Without loss of generality, the proposed approach is step-wise illustrated on real-time systems monitored by software controllers. Patterns are proposed to cover need expression, requirement capture, use case driven analysis and design.

No abstract