COMPASS White Papers

COMPASS white papers present a short, entry-level summary of key topics and outputs from the project. The white papers published to date are listed below and can be accessed by cliking on the title.

  • WP01: Guidelines for SoS Requirements
  • Authors: Simon Perry, Jon Holt: Atego, UK

    We propose a model-based approach for Systems of Systems Requirements Engineering, which consists of three main areas: a framework for model-based requirements engineering (MBRE); extensions to this framework to give specific coverage for system of systems projects; and a set of processes. This white paper summarises the underlying SysML model of the extended requirements framework and requirements processes described within.

  • WP02: SysML Blocks in CML
  • Authors: Alvaro Miyazawa, Lucas Lima, Ana Cavalcanti: University of York, UK

    SysML supports modelling various aspects of a system, and in recent years, SysML has increasingly been supported by a number of tool vendors such as IBM, Atego and Sparx Systems. Our aim is to support the application of formal analysis tools and techniques at the level of the graphical notations used in current industrial practice. In particular, in this white paper, we present our results on formalising the notion of SysML blocks including their related elements such as associations, compositions, generalisations, ports, interfaces and connectors.

  • WP03: SysML State Machines: a formal model for refinement
  • Authors: Alvaro Miyazawa, Ana Cavalcanti: University of York, UK

    This white paper follows on from COMPASS WP02 (SysML Blocks in CML) to present a denotational semantics of SysML state machine diagrams using CML. We focus on the relationship between block definition and state machine diagrams, based on a modelling pattern where a state machine diagram is used to define the possible behaviours of a block. We define the semantics of an extensive subset of state machine constructs, the choice of which is based on actual usage in examples and case studies.

  • WP04: A Dwarf Signal in CML
  • Authors: Simon Foster, Jim Woodcock: University of York, UK

    This white paper presents an introduction to the COMPASS Modelling Language (CML) using a model of a Dwarf Signal. The paper introduces the states of the signal and the properties that must hold to ensure safety of the signal, and then introduces the types, functions and processes that model the state, safety properties and reactive behaviour in CML. To demonstrate that such a system satisfies the contract imposed by its safety properties, the COMPASS theorem prover (based on Isabelle/HOL) can be used. Mechanisation of the example in the theorem prover is currently underway.

  • WP05: Modelling Patterns for Systems of Systems Architectures
  • Authors: Claire Ingram, Richard Payne, Simon Perry, Jon Holt, Finn Overgaard Hansen, Luis D Couto

    This white paper is an initial report on modelling patterns and architectures for system of systems (SoSs) and their constituent systems (CSs). We explain the background to architectural styles or patterns and introduce an initial set of five architectural patterns suitable for SoS design. SoS engineering presents some particular challenges for the architect, which should be taken into account. Each pattern that we introduce is illustrated with an SoS example, and we also identify the aims of the pattern.

  • WP06: An Introduction to Systems of Systems: Underlying Concepts
  • Authors: Claire Ingram, Alexander Romanovsky

    This white paper introduces some key concepts relevant to our work in model-based techniques to support development and maintenance of systems of systems. It is intended as a suitable starting point to introduce the key challenges facing engineers in systems of systems (SoSs), particularly when considering the application of model- based techniques. We provide pointers to other relevant COMPASS deliverables which provide further detail on some areas. This white paper makes a suitable starting point for reading about model-based techniques in systems of systems, and a good introduction to COMPASS for those who are interested in reading more about the project or more about a specific area.

  • WP07: An Introductory Comparison of COMPASS Case Studies
  • Authors: Claire Ingram, Alexander Romanovsky

    This white paper is intended as a basic introduction to the four COMPASS industrial SoS case studies. The four case studies are compared side by side, in terms of their architectures, SoS classification and various SoS-relevant properties, such as how independence or autonomy are exhibited by the constituents, the distribution experienced by the constituents, the nature of emergent behaviour and whether dynamic reconfiguration is employed, the interdependence of the systems, and how they are affected by evolution.

  • WP08: Traceable Engineering of Fault-Tolerant SoSs
  • Authors: Zoe Andrews, Claire Ingram, Richard Payne, Alexander Romanovksy, Jon Holt, Simon Perry

    Systems of systems (SoSs) are characterised by a challenging combination of continuous evolution, emergent behaviour and distributed, autonomous and independent constituents. The development of SoSs that can tolerate faults and harmful events is hampered by these and other complexities. Currently there is little in the way of methods or tools to help SoS developers to design fault-tolerant SoSs. In this white paper we introduce a structured approach for capturing the fault-tolerant aspects of an SoS at the architectural phase of design, the COMPASS fault modelling architectural framework (FMAF).

  • WP09: Case Studies of SysML to CML transformations
  • Authors: Lucas Lima, Alvaro Miyazawa, Ana Cavalcanti

    In this document we present overviews of the case studies used to exercise the SysML to CML transformations. We performed three case studies: the leadership election protocol, the dwarf signal and the producer- consumer problem. The SysML models of each case study are available here.