The Apdex Application Performance Index is a performance metric for web pages that has been created by the Apdex organization, an industry-sponsored technology promotion group. The Apdex Index seeks to provide an unambiguous way to compare the performance of websites, and to measure the relative performance of pages within a website.
The Apdex Index is based entirely on relative page loading times, and on a pre-defined threshold time value T (recommended T valud is 4.0 secs) below which a user is presumed "satisfied" with the performance. Pages that load slower than four times T (16 seconds, for example) are called "tolerating", and anything slower is called "frustrated".
The index formula is
Apdex-Index(T) = ( #satisfied + ( #tolerating / 2 )/ ( #total ) )
A typical application of the Apdex Index is to rank order Business IT Alignment when different parts of a website (i.e. subwebsite) are aiming at difference performance levels.
Step By Step Instructions
Here are the steps to follow to have eValid calculate the values you need to compute the Apdex Index for you.
Interpreting the Scores
According the the Apdex website, you should interpret the scores following this table:
Range Score 1.00 - 0.94 Excellent 0.94 - 0.85 Good 0.85 - 0.70 Fair 0.70 - 0.50 Poor Below 0.50 Unacceptable