ABSTRACT
Cost estimates, budgets, WBSs, schedules, quality, and risk are interrelated. Ideally, cost estimates are based upon elements of the WBS and are prepared for each work package. When the cost cannot be estimated because an activity is too complex, the activity is broken down further until it can. When the work is ill-defined or uncertain, the estimate is initially based upon judgment and is later revised as information becomes available. Project schedules dictate the need for resources and the rate of expenditures, but the converse is also true: constraints on resources and working capital dictate the schedules. Imposing practical constraints on costs is necessary to create realistic project budgets; failing to do so results in projects being completed at exorbitant expense, or terminated prematurely due to lack of funds. Both occurrences are relatively commonplace.
