Environment Budget and Cost Analysis
Environment Budget and Cost Analysis
This domain tests how you build, justify, and compare budgets and how you analyze costs. Questions often ask which cost is relevant, how to treat inflation and discounting, and how to explain a variance between planned and actual execution.
Core rules
- Budget formulation. A budget submission ties workload or requirement to a cost estimate, phasing, and justification. It must state assumptions, base year, inflation, and period. A baseline is the approved time-phased plan; changes require documented adjustment.
- Cost estimating methods. Analogy uses similar programs; parametric uses cost-estimating relationships; engineering build-up estimates labor, material, and overhead; actuals use historical invoices. Use the method supported by available data and document uncertainty.
- Relevant cost. Compare incremental cash costs. Direct costs are traceable; indirect costs must be allocated on a causal basis. Sunk costs are irrelevant; opportunity cost is relevant even when no cash moves.
- Life-cycle cost. Include acquisition, operations, maintenance, sustainment, and disposal. Do not compare only initial price.
- Discounting. OMB Circular A-94 provides discount rates. Use nominal cash flows with a nominal rate, or real cash flows with a real rate. NPV is the present value of benefits minus costs; a higher NPV is preferred among feasible alternatives.
- Execution analysis. Compare obligations and outlays to plan, explain price, quantity, and schedule variances, and distinguish a timing variance from real cost growth.
Worked example
A lease costs $120,000 per year for five years. Buying costs $450,000 now plus $20,000 per year in O&M. At 5%, the five-year annuity factor is 4.3295. Lease PV = $120,000 × 4.3295 = $519,540. Buy PV = $450,000 + ($20,000 × 4.3295) = $450,000 + $86,590 = $536,590. The lease has the lower life-cycle present value by about $17,050. Without discounting, lease payments total $600,000 and buy costs total $550,000, so the decision reverses. That reversal is why an undiscounted comparison is a trap.
Traps that cost marks
Mixing real cash flows with a nominal discount rate; comparing alternatives with different service lives without an equivalent annual cost; ignoring residual value or disposal cost; treating fixed overhead as variable; using obligations as a proxy for cost; and omitting escalation from outyear estimates.