Defining KPI’s in Performance Testing

When somebody asks “What is testing?”, There are many answers to it. My preferred answer is; “comparing the outputs according to the expected one and checking whether the requirements are fulfilled or not.” That’s an easy answer when it comes to functional testing. What about a non-functional test such as performance testing where requirements are not defined clearly? Everybody wants their website to respond fast with %100 stability. Your site or app can be fast, but it can misinterpret a request during a high load and order the wrong shoe size for your customer or vice versa. We want [...]