What is the value of a testing group? How do you justify your work and budget?

Testing is a method used for revealing defects in s/w and for establishing that the s/w has attained a specific degree of quality.

The s/w testing group's major objective is to ensure that the s/w is doing what it is supposed to do as well as the s/w is not doing what it is not supposed to do. With this objective, it is clear that it is essential to have a divide group for testing the s/w other than the group which developed it.