In the previous part of the article Improving Quality of Project Estimation, six guidelines for improving project estimates were presented. Experience in this world tells us that estimates sometimes do not materialize as planned and to compensate for this problem, project managers might end up readjusting their estimates by adding 20 percent or more. But why after all the efforts that have been put on detailed estimates do these numbers slip? In this third and final part of the article, we discuss four reasons for this dilemma.
In the previous part of the article Improving Quality of Project Estimation, we highlighted nine important factors that need to be considered when making estimates. In this second part of the article, we present six guidelines that will hep project managers develop better quality of estimates and avoid common pitfalls in practice.
This post is the first part of the article Improving Quality of Project Estimation. It highlights nine factors that influence the quality and accuracy of project estimates.
It is clear that estimating a project is important for the project manager to determine how long the project would take, to figure out how much the project would cost, to decide whether the project is worth doing, to measure variances against the baseline plan, and to take corrective actions. However some project managers nowadays tend to put minimum effort on their estimations which is the primary reason why their projects slip or fail to be delivered. Although achieving accurate estimates is desirable, there still remain a hidden uncertainty that can not be factored. Besides, while accuracy in estimating incurs extra costs and inaccuracy leads to unpleasant outcomes and customer discontent. the process of project estimating then becomes more like a balance of benefits between the two.
This post builds on the principles discussed in the article Calculating Optimum Cost/Time Project Schedule to calculate the optimum cost/time schedule for the Whitbread World Sailboat Race project. It demonstrates how to construct a priority matrix for the Whitbread World Sailboat Race project to determine whether each of the criteria (time, performance, cost) can be constrained, enhanced, or accepted. Based on this matrix, it then calculates the optimum cost/time scheduling to determine whether the project can be completed within 45 weeks and within the planned budget of 3,200,000$.