CSI’s project-delivery and facility-management perspective emphasizes that O&M budgeting should be grounded in real, documented performance and cost history wherever possible. The facility manager is the team member who typically maintains:
Utility bills
Maintenance contracts and work orders
Repair and replacement histories
Staff, labor, and consumables costs
These form a historical record of actual O&M costs, which provides the most reliable basis for forecasting future O&M budgets.
Technical guidance on O&M cost analysis similarly stresses that:
Agencies “should maintain O&M cost records†that document baseline costs.
When defining an O&M cost baseline, it is recommended to use as much historical data as possible, and that historic O&M costs and actual site data should be used wherever possible.
Research on O&M budgeting practice has found that historical-based budgeting predominates among budgeting bases used in real facilities.
That is exactly what Option D describes: the facility manager’s historical record of actual costs is the correct and most defensible basis for making O&M budget decisions.
Why the others are less appropriate from a CSI/CDT standpoint:
A. Architect/engineer’s projected operating costs – A/E projections can be useful at early planning stages, but they are estimates, not verified costs. Once a facility has operating history, the A/E’s projections are secondary to actual cost data.
B. Construction manager’s life cycle analysis – Life-cycle cost analyses are valuable for choosing systems and strategies, but they are models and assumptions, not the primary budget baseline once real cost data exist.
C. Estimator’s preliminary project description – A Preliminary Project Description (PPD) is a design-stage estimating and scoping tool, not an operating-cost record. It has no direct tie to actual O&M performance.
Therefore, under CSI-aligned practice, the facility manager’s historical record of actual costs (Option D) is the correct basis.
Core CSI-aligned references for this question (no URLs):
CSI Project Delivery Practice Guide – chapters on facility management and life-cycle considerations.
DOE/FEMP guidance on O&M baselines and cost savings, stressing use of historic O&M cost data and actual site data.
Research on O&M budgeting showing predominance of historical-based budgeting.