If a detailed estimate is NOT available to assist in the formulation of activity durations...

When detailed estimates are unavailable, historical production rates can provide reliable data for estimating durations based on past projects with similar work.

Option A (Eichleay formula) is for overhead cost allocation.

Option C (Time impact analysis) evaluates delay impacts, not durations.

Option D (Black-Scholes model) is irrelevant in this context.

Historical data usage is a recognized method in project planning and scheduling practices​​.