COST, SCHEDULE, AND TIME VARIANCES AND INTEGRATION

This paper demonstrates detailed schedule- and cost-control relationsh ips at the activity/cost-account level using generic microcomputer sof tware to budget, track, and control projects. Time variances are intro duced to describe differences between scheduled times and actual times for activity and project performance. Variances are the sum of more d etailed variances, and variances can be calculated and reported at dif ferent levels of detail, whether for activities and cost accounts or f or a project as a whole. Activity/cost-account budgets sum to project budgets, and variances sum to project variances. A unified nomenclatur e and parallel budget and variance structures allow integration of cos t and schedule control for projects that share common work breakdown s tructures. Budget, actual, and variance values of cost, progress, and time are combined in a single figure to demonstrate integration at the activity/cost-account level. Equation development is augmented with c omputer implementation details for generic spreadsheets or custom appl ications. Examples are presented for a single element from start to co mpletion and for a project of four elements.