As a QA our job is to ensure quality, however, all too often I hear about a small change, and the testing that a QA has said is needed is massive. I feel that QAs have a tendency to say to test everything when they don't necessarily understand the change, when with a few questions we can isolate the change down to a specific system and come up with an appropriate 10 minute test strategy.
Unfortunately, I think this comes out a lot as the QA is scared to ask exactly what the change is, what the affected systems are, and in all honesty no one should be afraid to ask if they don't understand anything. On the flip side, whoever you ask, you shouldn't take their response as gospel, do some investigation work yourself until you fully understand the risks and the affects this change will have.
I've experienced a number of scenarios where I've questioned the amount of testing or the type of testing that is being completed on a task. For example, a database change will very rarely (if ever) require cross browser testing, or a small change (ie. adding a link to a page) in one part of a system will not require regression testing of the whole system, but all too often this is something that is done and not challenged enough unfortunately.
There needs to be clear lines about what is in scope for testing and what is out of scope, and the risks that are associated with not testing (if any). The risk of not testing a database change cross browser is negligible (depending on the change of course).
Alas, I am not just talking about functional testing, a lot of the time, non functional testing, such as performance testing is performed when it's not necessary. To rectify we need to talk to other stakeholders, talk to developers, don't be afraid to not understand something at first, only through asking questions will we learn.
What can we do to rectify this?
We as QA need to be a lot smarter about what we test and how we test, or else we will get a bad reputation for being slow workers, for not testing efficiently, or get labelled as inconsistent. If one person says to do it this way, and another person on another team says to test something similar in another way, it makes everyone look bad. As a QA department consistency across teams will improve the perception of QA across the IT department, and I've mentioned before this is an area that is often lacking, be it rightly or wrongly, and we should do all we can to improve this.