There is a tool on codeplex that is well know about with the tech guys who analyze system performance issues but it’s a handy tool for using in pre-emptive monitoring when you are doing UAT, System testing etc for an implementation. You can find it here

http://dynamicsperf.codeplex.com/

Add it to your kit bag of tools as well as the trace parser that is in the product. As well for on-going monitoring the diagnostics service that is part of Lifecycle Service. As well if you want to use System Center for on-going monitoring with the MOM pack for Dynamics AX.

Cheers

Lachlan