How to Estimate Testing Time/effort Accurately?
Here are the methods discussed in this session:
Best Guess – This technique is purely guesswork and based on the some sort of experience. The method is very common, but since it is based on your gut feeling, its uncertainty contingency is probably around 200% or even higher.Ad-hoc method – The test efforts are based on tentative timeframe. The timeline set by managerial or marketing personnel or by client without any guess/experience. Alternatively, it is done until the budgeted finances run out. This is very common practice in extremely immature organizations and has error margins of over 100% at times.Experience Based – Analogies and experts:
Metrics collected from previous tests.
You already tested similar application in previous project.
Inputs are taken from Subject Matter experts who know the application (as well as testing) very well.
Work Breakdown Structure – It is created by breaking down the test project into small pieces. Modules are divided into sub-modules. Sub modules are further divided into functionalities and functionalities are divided in sub-functionalities. Review all the requirements from Requirement Document to make sure they are added in WBS. Now you figure out the number of tasks your team needs to complete. Estimate the duration of each task.
Delphi technique – Same as above WBS. Here functionalities and each task are allocated to each team member. Then team member gives estimate that they will take this many hours to complete the task. Averagely, this technique gives good confidence in the estimation. This technique can be combined with other techniques
Function Point/Testing Point Analysis: The FP technique is a direct indicator of the functionality of software application from the user’s perspective. This is the most accepted technique used to estimate the size of a software project. Base of this technique is function point technique.
Percentage distribution – Here all the phases of SDLC are divided in parts and assigned effort in %. Like –
Project management 7% Requirements 9% Design 16% Coding 26% Test (all test phases) 27% Documentation 9% Installation and training 6%