Cost Estimating Approaches - 2
Parametric
- Sometimes known as "factored" estimate
- Similar to gross comparison
- Also top down, but more and better data available
- I.e. "parameters" of individual systems or elements
- Based on statistical relationships between historical costs and relevant project variables
- E.g. physical size, capacity, performance, output etc
- Results in a "feasibility" or "preliminary" estimate
- Target range: -15% to +25%