“…As a result, managers of software development projects increasingly recognise the importance of planning and estimation (Lederer and Prasad, 1995;Deephouse et al, 1996) for the successful completion of their projects. However, although they have many sophisticated tools at their disposal, many systems are still delivered way behind schedule, cost far more to produce than original budget estimates, and fail to meet user requirements (Johnson, 1996;Lederer and Prasad, 1995;Simmons et al, 1993;Barki et al, 1993). It has been reported that, on average, software systems are delivered a year behind schedule, only 1% of software projects finish on time and to budget, and more important, 25% of all software-intensive projects never finish at all (Stockman and Norris, 1991).…”