ABSTRACT
Cost estimates are an essential factor in pricing external commercial projects and in the business plans of internal investment projects. For commercial projects, the actual project contract price may be arrived at after complex considerations depending on many things, but the project cost estimates will always be a key factor. Entirely accurate cost estimates happen sometimes by chance, but all estimates rely to some extent on judgement and it is really never correct to talk about the accuracy of estimates. The reliability of any cost estimate will obviously be at most risk of error when a project begins, with many unknown quantities lying ahead. It is always recommended for the purposes of reporting and control that the cost estimate of any project should be updated at stages throughout the lifecycle. Cost estimates have to be tabulated and recorded so that they can be kept safely for subsequent reference.
