Analogous Estimating – An estimating technique that uses values or attributes of a previous, similar project as the basis for estimating the same parameter or measure for a current project.
Key Characteristics:
- Top-down approach: Estimates are made at a high level using overall project parameters
- Historical data driven: Relies on actual data from completed similar projects
- Expert judgment: Requires knowledge to identify truly comparable projects
- Early project phases: Most useful when limited detailed information is available
- Less accurate: Generally less accurate than other detailed estimating techniques
How It Works:
- Identify similar past projects
- Analyze historical data (cost, duration, resources)
- Adjust for differences in complexity, size, or other factors
- Apply the adjusted values to the current project
When to Use:
- Project initiation: When detailed information is not yet available
- Rough order of magnitude estimates: For preliminary planning
- Limited time: When quick estimates are needed
- Similar project history: When organization has relevant historical data
Advantages:
- Quick and relatively inexpensive
- Useful for high-level planning
- Good for initial feasibility assessments
- Leverages organizational experience
Disadvantages:
- Less accurate than detailed methods
- Requires truly comparable projects
- May not account for unique project aspects
- Dependent on quality of historical data
Example:
A software company completed a mobile app project in 6 months for $200K. For a new similar mobile app project, they estimate 6-7 months and $180K-220K, adjusting for slightly different complexity.
Related Terms:
- Parametric Estimating: Uses statistical relationships and project parameters
- Bottom-up Estimating: Estimates individual components then aggregates
- Three-Point Estimating: Uses optimistic, pessimistic, and most likely estimates
- Expert Judgment: Professional opinion based on experience
Also Known As:
- Top-down estimating
- Historical estimating
- Comparative estimating
