We have spent a great deal of time on production application performance management (APM), but there is an entire market that focuses on pre-production performance testing. Our testing focused on production support teams, not development. There are several software vendors that provide tools to help developers isolate the problem if operations can't solve it. BMC Software offers AppSight, which is used alongside testing tools to capture problems before applications are released to production and improve initial quality. HP/Mercury also offers HP Diagnostics software and LoadRunner. These tools can help organizations accurately measure the performance of every tier of an application as well as the underlying server and components of the system. Tools like these are valuable for organizations that have mission-critical custom applications, and production-based APM tools may never find the root cause of the problem.