Single-Point Estimates
A single-point estimate is a specific numerical value assigned to an uncertain quantity in project management, cost estimation, or risk analysis. It represents a best guess or most likely value for a given parameter, such as time, cost, or effort required to complete a task.
Key Aspects of Single-Point Estimates:
- Fixed Value – It provides a single number instead of a range (e.g., "Task A will take 10 hours").
- Simplicity – It is easy to use and communicate.
- Assumptions-Based – It often relies on expert judgment, past data, or simple calculations.
- Risk of Inaccuracy – Since it does not account for variability or uncertainty, it can be misleading if the actual value deviates significantly.
Example:
A project manager estimates that developing a new software feature will take 15 days based on past experience. This is a single-point estimate because it does not consider best-case or worst-case scenarios.
Alternative Approaches:
- Three-Point Estimation (PERT) – Uses optimistic, pessimistic, and most likely values to account for uncertainty.
- Range Estimates – Provides a minimum and maximum to reflect variability.