The use and limitations of mathematical models in the planning and control of construction projects

The two major parameters associated with the planning and control of construction projects are time and cost. Modelling these parameters separately presents many difficult problems. The problem of optimizing the relationship between the two is even more complicated and earlier researchers have suggested a variety of models. Models are, in a sense, an attempt to initiate a systems approach to problem solving and decision making. The aim is to try to capture the major components and the interactions of a system. Having developed the model it is possible to obtain valuable insights into the behaviour of a system with possibilities of optimizing its performance. This paper considers the general problem of modelling time and cost and examines some of the conditions and limitations of the modelling process. The overall objective of this series of papers is to find not only a way in which the time cost parameters can themselves be modelled in dynamic and reasonably precise terms, but also to demonstrate the ways in which time and cost are inter-related and how the inter-relationship changes with the expansion or the diminution of the two parameters. The ability to capture and respond to the dynamic nature of the situation has been considerably enhanced by advances in computer technology, particularly in terms of the relatively low cost and interactive nature of the micro-computer.