Like beauty is in the eye of the beholder, optimal application performance is in the experience of the end user. It's a subjective matter that can bewilder network managers trying to ensure every app performs as its end users expect. And while the process of determining what optimal application performance is can be ambiguous, it is crystal clear when the goal has not been met and end users are complaining about slow service and non-responsive applications.

"There are logical limitations that apply to every application across various organizations. Everyone assumes the faster the better, but it's good to calculate the end-user expectations in your specific environment so you're not working to achieve an unreachable goal -- that doesn't really matter to your end users as much as you think," says Charles Thompson, manager of systems engineering at Network Instruments, a maker of network troubleshooting and analysis tools. (Compare Web Site Application and Performance Management products)

For instance, a call center location that is all about call processing would place a higher priority on accessing customer data than an end user that doesn't field such calls in their daily work. According to Thompson, network managers need to baseline that normal behavior of applications in their environment and determine the response times end users expect from their applications. What end users can live with in terms of application performance can sometimes be more realistic than what network managers assume.

"There are thresholds that one organization would consider bad, but that might be perfectly suited for another organization," Thompson says. "Network managers need to look at the deviations from what is considered normal in their organization and not set expectations that might not apply to every application."

Another speed bump organizations could run into when looking to optimize application performance is unexpected usage. While network managers know to expect spikes in e-commerce applications around holiday shopping seasons or streaming video applications following specific sporting events, sometimes applications undergo increased usage that impacts performance and that type of trend can fly under most network managers' radar.

Denise Dubie is senior editor with Network World.