Monday, August 29, 2011

Does extrapolation in estimation work?

How do you estimate test automation efforts for building a regression suite for functionality that is already in Production?

The approach I am following is:
> Get some level of understanding about the domain
> Look at a subset of existing test cases of varying complexities and sizes
> Estimate the effort for each of them and also identify the complexity involved in each, with the risks and assumptions.
> Identify some obvious spikes / tech tasks that will be needed
> Extrapolate the estimates
> Add 10-15% buffer in the estimates for unknowns.

And presto!! .... I have my estimates for the task on hand.

Is this approach right? 
Is extrapolating the estimates going to give valid results?
What can be different / better ways of getting the results required?

1 comment:

  1. Yes. Extrapolation works if we assume a risk coefficient to this estimate as to how much the median(extrapolated estimate) can swing between the low and high ranges. By this way, the actual estimate should be within the range if there are no unforeseen /overlooked issues.