SysML

Mechatronic design procedures must therefore utilize the potential of interdiscipUnarily cooperating development teams in the sense of concurrent engineering (van Brussel 1996) in order to obtain a holistically optimized product. A challenge that has to be mastered in this context is the creation of a universal nomenclature in order to facilitate the communication between the technical disciplines involved. Moreover, a uniform concept for the description of the interactions between the different subsystems is required. Function-oriented description languages like UML or SysML fulfill this requirement on an abstract level and can thus be used for the design of the superordinate function structure. Furthermore, the appropriate involvement of optional external development partners is an absolute condition for a successful mechatronic development project. 

Automating the synthesis of AltaRica Data-Flow models from SysML... 

The purpose of System Engineering (SE) is to schedule techniques to develop solutions in response to diverse stakeholders needs (Friedenthal et al. 2008). Those needs include reliability and safety aspects. Model-Based System Engineering (MBSE) (Estefan 2008) is nowadays considered as the best approach for the design of complex systems. It is supported by methods like the Object-Oriented System Engineering Method (OOSEM) (Lykins et al. 2000) for which SysML is well-adapted. 

The remaining of this paper is organized as follows. In the second section, we will discuss the integration of reliability analysis in SE frameworks. In section 3, we will present the method we developed to integrate reliability studies in a SE development process. Sections 4 and 5 will introduce the AltaRica DF language and expose the translation created with SysML. In section 6, we will exemplify the approach by continuing a smdy presented in (David et al. 2009). 

One of the most popular methods is the OOSEM, using SysML as a supporting language and mainly developed by the International Council on Systems Engineering. It is an iterative approach covering the following set of activities ... 

The aim of our work is to be able to analyse real conception models expressed in SysML and to perform the validation of safety and reliability requirements. 

Hazard Analysis. The second assumption is that developers have access to information on the dysfunctional behaviour of the components usually utilized in design. This base of information can be the result of studies on previous exploitations of similar components in systems already in use. In (David ef a/. 2009), we proposed a way to formalize this database using SysML. If such a database is unavailable, the process will contribute to building one, but the automatic phases will be less efficient. 

SUPPORTING ALTARICA DF MODELS CREATION WITH SYSML ANALYSIS... 

Considering that the model has been constructed with the two stated modelling rules, an automatic synthesis of the structural part of the AltaRica DF file could be performed. This step reUes on simple file analysis and translation rules. The analysis can be performed thanks to the exportation files furnished by the SysML tools. Those files exploiting the formalized XMl format provide the hsts of model elements. The exploitation techniques of these files have been given in (David et td. 2008, 2009). 

The strucmral view of the system must then be completed by the expression of the system behaviour. During the previous phases of the SE method, the functional behaviour has been described. The first task to perform is to translate this behaviour in the AltaRica DF model. For this phase, we assume that the behaviour has been allocated to the architecmre. We can thus add a rule to depict a functional modelling approach well-suited to prepare risk and reliability analysis, which is the allocation of the behaviour to precise architectural elements. We can notice that those allocation steps are clearly parts of the OOSEM, where logical nodes are allocated to physical nodes . The behaviour of AltaRica DF nodes is written in assertions and transitions as presented in section 4. The task of behaviour modelling consists in identifying the SysML elements that reflect the events, affectations and guards that constitute the assertions and transitions. 

SysML element, diagram type and element properties. Usage in AltaRica DF node behaviour description... 

We observe that it is possible to underline all the relevant parts of the SysML model to analyse for the users. Nevertheless, it is only possible to guide the expert exploitation of a huge model and to furnish propositions of translation. For example, by analysing the variables natures to consider if the constraints... 

David, P. Idasiak, V Kratz, F. 2008. Towards a better interaction between design and dependability analysis FMEA derived from UML/SysML models. Proceedings ofESREL 2008 and 17th SRA-EuropeAnnual Conference, Valencia, Spain, Sept 2008. 

David, P. Idasiak, V Kratz, F. 2009. Improving Reliability Studies with SysML. Proceedings of the 55th Annual Reliability and Maintainability Symposium, RAMS 2009, Fort Worth, Texas, USA, Jan. 2009. 

Friedenthal, S. Moore, A. Steiner, R. 2008. A Practical Guide to SysML The Systems Modeling Language. The MK/OMG press, Elsevier. 

SysML modelling of safety critical multi-technological systems... 

To overcome these disadvantages we use in this paper SysML for modelling multi-technological systems. In a case study we demonstrate how to model parts of a fuzing system. The objective of the paper is also to show how SysML can be gainfully used to prepare later safety analysis of given systems. 

An outline of the paper is given. Section 2 describes a general approach how a SysML model of a system can be built. In particular order for the generation of diagrams is proposed. Section 3 describes the generation of selected diagrams within a case study on fuzing systems. Section 4 summarizes and concludes the paper. 

Main part of a SysML modelling procedure is the determination of modelling sequence. The decision of what how and in which order to model is driven by the following principles ... 

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