Claire Ingram

Modelling patterns for systems of systems architectures

This paper presents an initial report on modelling patterns and architectures for system of systems (SoSs) and their constituent systems (CSs). Fundamental architectural principles for systems and SoSs and relevant work published so far are discussed and summarised. We introduce an initial set of five architectural patterns suitable for SoS design, illustrating each pattern with an SoS example and identifying how it meet some basic SoS aims. Finally, we summarise our plans for developing these ideas in the future.

Cost-Benefits of Traceability

Traceability can provide substantial benefits, but many software development projects fail to employ best practise in traceability. A major factor in this is the relatively high cost of traceability and the difficulty of assessing its long term financial benefits. We discuss techniques for implementing requirements traceability in such a way as to maximise the potential benefits whilst minimising the costs, but still ensuring that trace data collected meets the needs of the project. Finally we suggest a simple, practical cost analysis for developing an appropriate traceability strategy, underpinned by value-based software engineering principles.

SysML fault modelling in a traffic management system of systems

Systems of systems (SoSs) are vulnerable to faults, for example arising as a result of the distribution and independence of their constituent systems. Our previous work has presented an initial framework for reasoning about faults and fault-tolerant design within an SoS at the architectural level, using a simple example of a single failure. In this paper we present a motivating example of an SoS within which failures of constituent systems (CSs) may lead to a degraded or partial service for the SoS. We discuss a possible extension to our earlier framework to allow an architectural engineer to reason about the fault tolerance of an SoS where CSs contribute negatively or positively towards a goal or an SoS-level failure, and where multiple SoS faults may interact to affect SoS service quality.