In the world of software testing and quality assurance, we all know the value test automation brings by improving test coverage, overall product quality and the tester’s productivity. But all of this value flows in and the return on investment occurs only when the automation code is robust and reliable enough to produce consistent results to catch product bugs. The term “product bugs” is very important here. If the automation code does not catch bugs (if this is truly because the product has reached a steady state and is largely bug free, then it is acceptable) or shows more false negatives (due to test code issues rather than product issues), there will be a lot of wasted effort including:

Test Automation Effort – code design, implementation and maintenance resulting in wasted time, cost and human resources

Triage time – involving the product team to look into the invalid bugs reported resulting in expended time, cost and human resources and more importantly the reputation of the test team

Resource Usage – machine, other infrastructure and software usage for automation execution

Source: http://www.ctoedge.com/content/testing-your-test-code