From a management standpoint, Test-Driven Development (TDD) can be a difficult sell. It involves a relatively large upfront investment, has no obvious business benefits, and (most important of all) the customer is paying for functionality, not tests.
Tempting as it is to cut testing in order to reach the next milestone in the project, it is a mistake because, as we’ll see, TDD can help us accelerate development and reduce costs over a project’s lifecycle.