When Should a Test Be Automated? 05

angelcc216

Brian Marick

Testing Foundations
marick@testing.com


My decision process uses these questions.

1. Automating this test and running it once will cost more than simply running it
manually once. How much more?

2. An automated test has a finite lifetime, during which it must recoup that additional
cost. Is this test likely to die sooner or later? What events are likely to end it?

3. During its lifetime, how likely is this test to find additional bugs (beyond whatever
bugs it found the first time it ran)? How does this uncertain benefit balance against the
cost of automation?

If those questions don’t suffice for a decision, other minor considerations might tip the
balance.

The third question is the essential one, and the one I’ll explore in most detail.Unfortunately, a good answer to the question requires a greater understanding of theproduct’s structure than testers usually possess. In addition to describing what you can dowith that understanding, I’ll describe how to get approximately the same results without it.

When Should a Test Be Automated?