Importance of Schedule and Cost Control
Stakeholders measure projects by how well they are executed within the project constraints or baselines. Schedule and cost (budget) are two of the major legs of the project constraint polygon. Without the schedule and budget baselines plans, one does not know where the project stands relative to planned schedule progress or planned budget performance.
I. Project Baselines
Stakeholders measure projects by how well they are executed within the project constraints or baselines. A baseline is an approved plan for a portion of a project (+/- changes). It is used to compare actual performance to planned performance and to determine if project performance is within acceptable guidelines. Every project has at least four project baselines. There may be others, depending on the project and definitions used.
Schedule and Budget are the focus of this paper and the terms activity and work elements are synonymous. Schedule and cost (budget) are two of the major legs of the project constraint polygon. Without the schedule and budget baselines plans, one does not know where the project stands relative to planned schedule progress or planned budget performance.
The schedule and budget baselines, along with other baselines, are developed in the planning phase of the project. The project plan is approved prior to execution by the project sponsor or an appropriate senior level manager. The project plan includes the budget and schedule. Schedule determines when work elements (activities) are to be completed, milestones achieved, and when the project should be completed. The budget determines how much each work element should cost, the cost of each level of the work breakdown schedule (WBS), and how much the total project should cost. Actual performance can be compared to these plans to determine how well the project is progressing or finished.
Schedules and budgets are interlocked, and most likely an increase in one causes an increase in the other.
II. Project Budget
The project budget is a financial plan for all project expenditures (cost). Success in project budget management depends on, amongst other things, the creation of a comprehensive, consistent, and reliable project budget. Some people want to use the term "accurate" in the above definition. But, the word "accurate" has no place in the project world. Reliable and consistent are the terms that should be used. By definition, the project budget cannot be accurate as it is an estimate. Normal ranges of project budget variability depends on the project, the organization, type of business (and many other factors) but usually falls within +/- 10%.
A. How to Develop a Project Budget
In the Project Management Body of Knowledge Guide® world, there are two processes to developing a project budget. The first process is Estimate Cost, which is often confused with the Determine Budget process. Both of these processes are normally preceded by a project management team planning process, which is executed as part of the Develop Project Management Plan. This planning process is known as the Project Cost Management or the Cost Management Plan. The Cost Management Plan outlines the processes involved in determining organizational cost categories, estimating, budgeting, and controlling cost, so that the project can be executed within the approved budget.
The Estimate Cost process is not only confused with Determine Budget but is also widely misunderstood. Many think that this process estimates the total cost of the project. But this is not correct, at least not directly. The Estimate Cost process estimates the cost for each of the work elements and records the basis of that cost. That is as far as Estimate Cost goes!
The second of the three processes in Project Cost Management is the Determine Budget process, which rolls work element cost upward, applies cost aggregation, applies project contingency, makes a cash flow estimate, and now you have a budget for the various levels of the WBS and the total project.
B. Why a Project Budget is Important
Based on the work above, we now have a budget for:
- Individual Activities
- Work Packages
- The Total Project
This level of detail allows a project manager (PM) to evaluate the budget performance of the project from the top down or from the bottom up. If a work package is running over or is in danger of over running the budget, the project manager can drill down until he/she finds the problem or potential problem. The drill down can be by the PM or in conjunction with the assigned team member.
One other very powerful tool that helps in the analysis of project budget performance is the Earned Value Method (EVM).