Systems Approach to Civil Engineering Decisions

While contemporary civil engineering projects are increasingly complex, the cognitive abilities of the decision maker remain limited. There is a conflict between the complexity that is required to describe a scenario with all its relevant properties and the limited number of ideas that can be included in rational considerations and decisions. A resolution requires the decision maker to construct a limited model that includes the most significant features. In this paper, a systems approach provides a general decision-making scheme that makes involvement in broadly based decisions accessible. This scheme is valid at all scales and in all classes of problems. This paper establishes a practical method for generating systems that contain all features relevant to a professional decision. The criterion of decision invariance is offered as a guide for establishing the size of the system model considered by the decision maker. It is argued that surprises cannot be avoided and must form an integral part of the decision.