Title: Systems of Systems Engineering and the Pragmatics of Demand
Authors: Boxer, P., Cohen, B. Anderson, W. & Morris, E.
Where published: IEEE 2008 International Systems Conference, Montreal
This presentation will illustrate how demands that are placed upon complex, open, systems of systems can be described within their contexts of use and how variations in compositional approaches can be related to variations in these demands.
Traditional systems engineering makes the simplifying assumption that the systems are closed – immune from disturbances (demands) that are not anticipated by the engineering process. These systems manifest capabilities that are specified during system design. However, complex systems of systems frequently violate this assumption and indeed are conceived to react to unanticipated demands. Such systems of systems are open – subject to demands for which traditional engineering processes cannot fully account and are able to compose capabilities at or near run time. Examples are systems of systems that have to support responding to emergencies, such as forest fires or asymmetric threats, such as in “power to the edge”.
We suggest that a new engineering approach is needed that enables collaborative composition by specifying or restricting systems of systems behavior at the time of use rather than at design time. To achieve this we at least need:
• Appropriate component models
• Use and context-focused composition strategies
• Ways to characterize demand
• Tools to facilitate composition
One problem with this engineering approach is how to determine the range of composition strategies that can provide the necessary agility to respond to future, unspecified demands. One barrier to predicting this range is that the context in which a capability is used directly affects the way users want the capability delivered. The articulation of a user’s demands in the form of their organization, constituting their pragmatics of use, which can be modeled. i.e. the user cannot know his or her needs directly, but rather can know them indirectly through his or her experience of their organisation in the form of demands.
What we propose is a process for describing demands within their contexts of use, and how variations in compositional approaches can be related to variations in these demands-in-context (pragmatics), thus giving a basis from which to evaluate the ability of systems of systems to respond to such variations, thus evaluating their agility.