A conflict between the use of estimating and planning tools in the management of information systems

This paper argues that there is a difference between how software development project managers perceive the task of estimating project costs and duration and the way in which commercially available estimating tools are designed to be used. A model of the early estimating/planning stages of a project (the EEPS model) is presented which suggests estimation could be first carried out either before or during the first detailed planning stage. A survey was carrried out which confirmed that project managers typically perceive the ‘true’ process of estimation as being part of planning. This result may explain why estimating tools are not widely used: planning tools are being used instead. By making a temporal distinction between the points at which project information first becomes available, however, it can also be seen that even planning must be driven by some assessment of the size and complexity of a project. At this point only estimating tools are available to provide such estimates. The conclusion seems to be that estimating tools do have a role to play in project management, but they must be explicitly task-based in order to fit the way in which project managers currently perceive estimation.