Order of magnitude estimates

I'm not a big fan of throwing around numbers when talking about testing. I understand that saying things like "We have 100 test cases" doesn't really communicate anything other than a number. However, I have found that using order of magnitude numbers can help communicate size and scope to other project/test managers when planning the project.

I find that as we're developing resource plans and course-grain timelines, orders of magnitude can help imply level of effort. If we're talking about scripted or automated tests, I'll talk about tens or hundreds of tests. If we're talking about sessions or charters, I'll talk in powers of two (2, 4, 8, 16, or 32).

Sometimes, when we think everyone's on the same page, we can quickly gauge each others understanding of how much testing might be involved. If we're talking about testing something and I'm not sure we have the same understanding of the amount of work involved, I might ask "How many tests do you think that is?" If you say tens of tests, and I'm thinking hundreds, that's a good indicator you and I need to get on the same page. We've identified an opportunity for talking about what our "tests" entail and what level of coverage we really want.
Test PlanningMichael Kelly