Estimate to Complete for Testing
I have been getting requests for some time now to supply 'estimates to complete' for the System Test execution phase for Projects. The requests are coming from the Development Team- they have a tracking process where each developer supplies the estimated effort to complete for their allocated build tasks. So they are asking for a similar figure from testers. Not so much at an individual level but at a Project level.
My opinion is that trying to supply this on an ongoing basis during test execution is very difficult. Unlike developers the tester's completion is influenced by the quality of the software, the turn around time for bugs and testing environment availability.
We of course do a Project testing effort estimate during the Project planning phase (like most organisations). What the Development team is after is an early warning of testing not completing on time. For me, the reports coming out of Quality Centre are enough to see if either the test case execution is behind or the bug count is very high and then investigate why.
Would appreciate any feedback or advice that could be offered re managing expectations. I have tried to explain this many times to more than one Project Manager/Development Manager but can't seem to get the message across. Alternatively if anyone has managed to measure this or something similar for testers I would be interested to know how it was done.
Thanks in advance.
Re: Estimate to Complete for Testing
I hope I have been able to understand the question
- You have access to the development effort for each module.
- You have access to the entire testing effort
You want to figure out the testing effort for each module.
Question - How did you manage to draw the overall testing effort without first figuring out the estimate for each module?
Allow me to explain:
1. There are 3 modules
2. Development estimates
Module 1 = 48 hours
Module 2 = 50 hours
Module 3 = 24 hours.
3. Total testing effort
Module 1 = formula for estimating module 1 testing effort
Module 2 = formula for estimating module 2 testing effort
Module 3 = formula for estimating module 3 testing effort
Total Testing effort = Sum of effort of all three modules.
The management decides that they want to defer Module 2 for a later release!.. They know how much development effort would have to replanned.
They would not be able to figure out how much testing time would have to re planned.
Different organizations have implemented different techniques for gathering estimates. Unfortunately, our experience made us learn that they are seldom accurate.
My suggestion -
If the business and technical risk of the project is not high, use the following formula
Testing effort for Module 1 = 1/3 of development effort for module 1
If the business and technical riskis high, then "normally" I tend to use 1.5 times of the development effort.
I also include a "safety" - which varies from 20% to 200% (this caters to business risk, technical risk, unplanned work disturbance, multitasking the resources across multiple projects)
Estimation is a messy business. With a little practice, I have managed to come up with near accurate estimates most of the time.
Yes - there are many "fancy" methods for estimation. A few books have been written on them too.
Hope this helps