System of Systems Acquisition Trade-offs

During System of Systems acquisition, organisations aim to satisfy their goals through the procurement of systems, people, training and processes. The most successful organisations undertake these acquisitions as efficiently as possible. For large organisations, a set of goals may be satisfied to varying degrees by any one of a large number of potential resource combinations, and so it is necessary to consider the trade-offs exhibited by each combination to find an effective System of Systems architecture. In this paper, we present an approach, supported by tools, that combines techniques from the fields of goal-modelling and multi-objective optimisation to effectively explore these high-level organisational trade-offs. The decision maker can state the organisational problems and provide high-level descriptions of the existing and acquirable systems using a custom domain specific language. The tool then explores the space of potential resource combinations using a multi-objective genetic algorithm and provides the decision maker with a Pareto front of acquisition plans that represent the best trade-offs between the various goals and costs. Furthermore, the technique and tool enables acquisitions to be scheduled to take an account of such factors as maintenance costs, existing system retirement dates, upfront costs for bringing new systems into service, the budgetary constraints of the organisation and how this affects the organisation's ability to satisfy its goals through the acquisition. The approach is evaluated on a realistic case study in which new systems are acquired to support a military scenario whilst considering the existing in-place systems and through-life implications. (C) 2014 The Authors. Published by Elsevier B.V.