Analogy-based estimations

Estimation by analogy is the simple idea that you can create accurate estimates for a new project by comparing the new project to a similar past project.

Here is a basic estimation by analogy process that will produce better results:

1. Get detailed size, effort, and cost results for a similar previous project. If possible, get the information decomposed by feature area, by work breakdown structure (WBS) category, or by some other decomposition scheme.

2. Compare the size of the new project piece-by-piece to the old project.

3. Build up the estimate for the new project's size as a percentage of the old project's size.

4. Create an effort estimate based on the size of the new project compared to the size of the previous project.

5. Check for consistent assumptions across the old and new projects.