MORE ABOUT COST ESTIMATING PROCESS ANALYZER PROJECTS: Accuracy estimates should become tighter as the project progresses

摘要

In last month's issue, we made the case for accurate analyzer system project cost estimates, discussed the common causes and special factors that influence analyzer system estimates, and presented best practices to ensure accurate analyzer system estimates (Control, March '07, p. 59, or at www.controlglobal.com/articles/2007/054.html). We'll now address estimate accuracy and cost by project stage, sources of estimating information, types of costs by work breakdown structure (WBS), and types of construction contracts. We recall from the first article in this series (Control, June '06, p. 49, or at www.control-global.com/articles/2006/112.html) that we can break the analyzer project life cycle into five chronological stages (see Table 1). We shall confine our discussion in this article to Stages 1 through 3.