Once a working benchmark is in place in your test infrastructure, be it a version of an application that can be run in a controlled environment or a subset of the algorithmic problem that an application tries to solve, regression testing can be performed. This ensures that no performance is lost during future code alterations.

Another purpose of the benchmark is to provide a small self-contained sandbox that can be used to tune the runtime environment in order to provide optimal performance for that particular application and to make sure that performance goals set for the software project are reached.

Whereas, in some cases, it may be obvious from benchmarking that parts of an application need to be rewritten using more efficient algorithms, sometimes it may just be enough to provide a more optimal runtime environment by tuning the JVM parameters.