Test estimation techniques

Approaches

1.Implicit Risk context approach
2.Metrics-Based approach
3.Test work breakdown approach
4.Iterative approach
5.Percentage of development approach

Implicit Risk context approach

Project manager (or) QA Manager to implicitly use risk context in combination with past personal experiences in the organization to choose a level of resources to allocate to testing

Risk context Factor:
a)Software quality levels
b)Software's intended use
c)Experience level of developers and testers




Metric based Approach

Track past experience of an organization various projects and associated test effort that worked well for projects.This past experience information can be used for further future test project planning.

Test work breakdown approach

Decompose the expected testing tasks into collection of small tasks for which estimates can at least in theory be made with reasonable accuracy.

Iterative approach

In this approach for large test efforts an initial rough testing estimate is made.once testing begins a more refined approach is made after a small percentage(eg 1%) of the first estimate's work is done.
Then a yet more refined estimate is made after a somewhat larger percentage(eg 2%) of the new work estimate is done. Respect the cycle as necessary/Appropriate.




Percentage of development approach

Some organizations utilize a quick estimation method for testing based on the estimated programming effort. For example If a project is estimated to require 1000 hours of programming effort, and the organization normaally finds that a 40% ratio for testing os appropriate
Then an estimate of 400 hours for testing would be used this approach may (or) may not be useful depending on the project to variations in risk personal,types of applications,levels of complexity etc.