Have you ever been affected by a slow loading or not responding application? According to recent studies a typical user is willing to wait up to 4 seconds and will often never return.
Obviously, performance is a crucial aspect of our business applications besides their primary objective to work properly. However, many treat it simply as an afterthought.
One project I was involved in recently was successfully launching a new account opening form application. In this project, both functional and non-functional requirements were tested methodically pre-deployment. In a collaboration between performance and development specialists, we implemented some significant optimizations which improved response times by a factor of 5.
All things considered, performance optimization can mean different things, but the value of building efficient code is clear. Those projects that consider non-functional tests in early stages reduce their costs dramatically and avoid frustrating fire-fighting at production.