Unless you are focused on optimizing the time to restart an application, the meters you might collect at application start are pretty useless as things are warming up. The first few transactions will find the disks nearly idle, queues empty, locks unlocked, nothing useful in cache, etc. As the work flows in, queues will build, buffers will fill, and the application will settle down after a short period.
There have been many math geniuses that have spent years trying to find a mathematical way to know when the warm-up period is over and you can start believing the data. To date there is no good mathematical answer. You just have to eyeball it. Fire up the application and let it run. Your eye will clearly note if, and when, the response times and utilizations stabilize. Ignore the data during the warm-up period.
Other helpful hints can be found in: The Every Computer Performance Book which is available at Amazon, B&N, or Powell’s Books. The e-book is on iTunes.