Which estimation technique uses historic data for quick estimates?

Which estimation technique uses historic data for quick estimates?

• A. Bottom-up uses historical data for quick estimates.
• B. Three-point uses single-point estimates.
• C. Analog uses historic data for quick estimates.
• D. Parametric uses optimistic/most likely/pessimistic estimates.

Answer: (C)

Analog estimation relies on historical data from similar projects to produce a quick estimate. By comparing the new project to past ones that are alike, you can approximate duration or cost quickly without detailing every task. This approach is fast because it leverages real outcomes from experience rather than building a full, bottom-up model. Bottom-up estimation requires breaking the project into many components and estimating each piece, which takes more time but yields greater precision. Three-point estimation uses three values (optimistic, most likely, pessimistic) to capture uncertainty, not just a single quick look at past work. Parametric estimation uses formulas based on unit rates and relationships, which is efficient but relies on a model rather than direct past-project comparison.

Analog estimation relies on historical data from similar projects to produce a quick estimate. By comparing the new project to past ones that are alike, you can approximate duration or cost quickly without detailing every task. This approach is fast because it leverages real outcomes from experience rather than building a full, bottom-up model.

Bottom-up estimation requires breaking the project into many components and estimating each piece, which takes more time but yields greater precision. Three-point estimation uses three values (optimistic, most likely, pessimistic) to capture uncertainty, not just a single quick look at past work. Parametric estimation uses formulas based on unit rates and relationships, which is efficient but relies on a model rather than direct past-project comparison.