AI planning research is now maturing and nding practical application in the commercial, industrial, engineering and defence sectors. This has led to a rapid expansion in the last couple of years of investment in this area. The plan representations which have emerged from the research have been found to be of bene t in a number of areas { even when the generation of a plan is not the primary concern. One way in which the research is being exploited is via the use of knowledge based plan representations to underpin systems which can use \knowledge rich" plans to improve their monitoring, analysis and advisory capabilities. Two applications using knowledge based plan representations will be described and the paper will introduce a further area in which plan representations may nd productive use. First, planit was an application in a company producing fuel tanker trucks and shows how the linking of knowledge rich representations of product process plans, project plans and shop oor jo...