The role of feedback dynamics in disruption and delay on the nature of disruption and delay (D&D) in major projects

The idea that small disruptions and delays can cause serious consequences to the life of a major project, well beyond that which might be easily attributed to their direct impact, is well established. Nevertheless, the nature of this 'delay and disruption' is still not fully understood. This paper discusses some of the issues and difficulties in gaining a full understanding. In particular it presents the variety of ways in which disruptions occur, and the variety of consequences that may unfold. It also focuses attention on a number of issues that arise when 'normal' methods of analysis of complex projects might be used, for example, the analysis and costing of change orders and the use of network analysis. The role of dynamic feedback and the 'portfolio effect' is introduced, particularly with reference to project acceleration and changing productivity.