Overview
Parametric estimation uses statistical relationships between historical data and variables to calculate estimates, applying mathematical models like "cost per square foot" or "hours per feature."
How It Works
Formula: Estimate = Unit Cost × Number of Units
Examples:
- Software: Hours per function point
- Construction: Cost per square foot
- Manufacturing: Time per unit
- Writing: Words per hour
Advantages
- Objective and repeatable
- Based on statistical data
- Scales easily
- Quick to calculate
- Improves with more data
Requirements
- Historical data
- Measurable parameters
- Statistical validity
- Similar conditions
- Reliable metrics
Common Parameters
Software Development
- Lines of code
- Function points
- Story points
- Features/modules
- Screens/pages
Construction
- Square footage
- Number of rooms
- Building height
- Material quantities
Content Creation
- Word count
- Page count
- Article count
- Video minutes
Time Tracking Integration
- Track time by measurable unit
- Calculate average rates
- Build historical database
- Refine parameters over time
- Improve estimation accuracy
