Architecture Modeling - SPES 2020

5.2.1.1 Model Based Development
Architecture Modeling
Model based development is today generally accepted as a key enabler to cope with complex
system design due to its capabilities to support early requirement validation and virtual system
integration. While initially the overhead introduced by additional modeling activities for specification
and design models and the costs of maintaining coherency of such models and their
implementation slowed down the introduction of model-based development, the benefits of such
frontloading of processes in achieving high-quality design and avoiding deep iteration cycles is
increasingly seen as key benefit by systems industries, with sector- and application-specific
penetration rates reaching close to 100% such as for primary and secondary flight control in
aerospace, and engine control or dynamic stability control in automotive. Methods used depend
on design layer and application class, such as the use of SysML or AADL for complete
system modeling, Matlab-Simulink for control-law design, and UML, Scade and TargetLink
for detailed design. Today’s state-of-the-art in model based design includes automatic codegeneration,
simulation coupled with requirement monitoring, co-simulation of heterogeneous
models such as UML and Matlab-Simulink, model-based analysis including verification of
compliance of requirements and specification models, model-based test-generation, rapid prototyping,
and virtual integration testing as further elaborated below. We also delay the discussion
of the additional role of model-based design in enabling design-space exploration, architecture
evaluation and platform-based design to the subsection addressing the challenge of overall
optimization of the system under development.
While thus model-based design is already today instrumental in improving product quality
and boosting productivity in complex embedded system design, it is largely focusing on architecture
and function. Non-functional aspects such as performance-, timing-, power- or safety
analysis are typically addressed in dedicated specialized tools using tool-specific models, with
the entailed risk of incoherency with models actually driving design and implementation, and
models used to assess such non-functional characteristics of designs. To counteract these risks,
meta-models encompassing multiple views of design entities, enabling co-modeling and coanalysis
of typically heterogeneous viewpoint specific models have been developed. Examples
include the MARTE UML profile for real-time system analysis [40] and the Metropolis
meta-model [21] (the term meta-model is intended here in the semantic domain, i. e., a sort
of abstract semantics, while in the traditional use of the term, meta-model is a structural concept
and corresponds to abstract syntax). Along the same lines, the need to enable integration
of point-tools for multiple viewpoints with industry-standard development tools has been the
driving force in providing the SPEEDS meta-model building on and extending SysML, which
has been demonstrated to support co-simulation and co-analysis of system models for transportation
applications allowing co-assessment of functional, real-time and safety requirements,
and forms an integral part of the meta-model-based interoperability concepts of the CESAR
reference technology platform 6 .
5.2.1.2 Virtual Integration
Rather than “physically” integrating a system from subsystems at a particular level of the righthand
side of the V, model-based design allows to virtually integrate systems based on the models
of their subsystem and the architecture specification of the system, which in particular explicates
the information flow between subsystems and the systems environment. Such virtual
integration thus allows detecting potential integration problems up front, in the early phases
6 http://www.cesarproject.eu/
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