Is PERT COST a useful costing system?
Having broken a project down into tasks for purposes of time control, it seems only logical that we should use that same breakdown for cost control. The resource assessment, required to estimate durations, could be used to generate a budget for each task – and hence a budget or “estimate of cost” for the complete project. Progress assessment for time reporting could be tied in with valuation assessment for cost reporting – avoiding duplication of effort and providing some assurance that the two processes are harmonized. This approach to costing – called PERT COST because of its early association with PERT networks on major defence development projects – is the basis for all the costing systems “built in” to Project Scheduling software, including PROPLAN. Despite this intuitive appeal, attempts to apply PERT COST concepts in the construction industry have been particularly unsuccessful.
