Jon Holt

Expanded requirements modelling - SoSACRE

This chapter discusses the SoSACRE Framework for modelling requirements for Systems of Systems. This Framework is an extension of the ACRE Framework that was described in the previous chapter. The SoSACRE Framework allows the context of both Systems of Systems and their associated Constituent Systems and allows them to be analysed in terms of consistency between them. The SoSACRE Framework also extends the Validation Views so that they encompass Systems of Systems. The SoSACRE was developed in 2011 and has been in use ever since on a variety of industry projects.

Interface Definition Pattern

The Interface Definition Pattern provides three viewpoints that enable the identification and definition of interfaces to be specified in terms of the structural aspects of the interfaces: the Interface Identification Viewpoint identifies each Interface, the Interface Connectivity Viewpoint shows the connection between Interfaces and the Interface Definition Viewpoint defines what is transferred across each Interface. The Pattern also provides two Viewpoints that enable the behaviour of Interfaces to be specified: the Interface Behaviour Viewpoint identifies typical scenarios showing how Interfaces are used and the Protocol Definition Viewpoint defines any Protocols to which Interfaces or Ports must conform. When using the Interface Definition Pattern, as a minimum at least one ICV and one IDV are needed to specify Interfaces, their associated Ports and the connections between them. Where the information on the IIVs is not a subset of that on the ICVs, then at least one IIV must also be produced. In practice, however, multiple IIVs, ICVs and IDVs would be produced along with Interface Behaviour View and, where necessary, Protocol Definition Views. Note here the use of View rather than Viewpoint. When using the Interface Definition Pattern, Views are created that conform to the Viewpoints.

Appendix C: Summary of diagramming guidelines

This section defines general naming guidelines that should be followed when producing SysML diagrams. When modelling Standards etc. or producing models for customers, any naming conventions described in the Standard or used by the customer should be followed. Two types of SysML diagrams are discussed namely: SysML structural diagrams and SysML behavioural diagrams.

Appendix A: Ontology and glossary

This appendix provides a summary of the model-based systems engineering (MBSE) ontology and the definitions of the concepts contained.

Introduction to model-based systems engineering

The world of systems engineering is changing. In recent years, the whole field of systems engineering has been seen as no longer an emerging discipline but as a valid approach to realising successful systems. Systems engineering is a broad field that encompasses many disciplines, can be utilised in many industries and can be applied across many and varied life cycles.

Appendix B: Advanced sequence diagram notation

This appendix gives a summary of some of the advanced notations that can be used with SysML sequence diagrams that allow the following to be shown: Parallel behaviour; References to other sequence diagrams; Alternative steps; Loops. The notation to allow these constructs are known as combined fragments. For full details, see Reference 1. Examples of the notation for each of these combined fragments showing how they are used are given in the following sections.

Enterprise architecture case study

The following sections are included: introduction; the meta-model; the ontology; initial viewpoints; generating views; the complete architecture view quagmire; and conclusions.