A framework for systems engineering design

Abstract

This paper follows on from the previous paper in the series and attends to the methodology of design as conceived within the whole-system whole-life dimensions of systems engineering. It assumes the concepts and general structure of systems engineering as outlined in the previous paper and goes on to elaborate the form and content of systems engineering from a design perspective.The paper begins by considering the systems engineering organization within the hierarchical structure for project design and management that has evolved from the one-time individual project engineer. Then the important relationships between entrepreneur/contractor, customer/owner, user are explored to illustrate why design in the system engineer's hands is dominated by overall cost-effectiveness optimized with respect to the future whole-life operations. The systems engineering design process is very similar to multiple-objective decision analysis as both designer and decision maker are faced by a similar problem: to find a way of organizing action and deploying resources so that a desirable future state is realized efficiently. The decision analytical process is structured to provide a framework for the systems design methodology itself. This follows using a top-down (hierarchical) approach in which overall system worth is determined with respect to clearly articulated objectives and evaluated with respect to a comprehensive multiattribute value criteria. Cost-effectiveness is disaggregated into its components of availability, dependability, capability and discounted whole-life cost. These in turn are related to the sub-design problems of operational performance, reliability, maintenance, logistic support, risk and impact analysis.