Consistent application performance: It's not always about speed
When developing applications, the response time is always an important metric. But inconsistent response times can often be more aggravating than slow sites. Make sure you take response time consistency into your application performance reviews.
Most applications include performance requirements that govern the acceptable response times of an application. So an enterprise might have a requirement dictating that a 97% of all response times should come in at less than five seconds. Unfortunately, these types of requirements alone are incomplete, as they overlook the fact that unpredictable or inconsistent response times can be just as frustrating to the user as a site that has slow load times.
More than fast response times, users want a predictable and repeatable experience from their applications. If each page takes two seconds to load, users will quickly acclimate themselves to this. So long as the response time of the application is within the realm of acceptability, users will adjust to the application's responsiveness, so long as that responsiveness is consistent.
However, if some pages load with sub-second response times, and other pages require two or three seconds to load, users will begin to notice the delays, with slow pages appearing exceptionally slow when encountered after pages that load exceptionally fast. The key is to not just deliver acceptable response times, but to also deliver consistent response times.
Standard performance testing software can be used to determine which pages are loading at rates outside of standard acceptable deviation. Developers should pay heed to these results, as delivering a consistent experience to the end user is just as important as delivering a fast and responsive experience.
