When evaluating a performance test report most of the times we are looking for the response time and specifically the Average response time.

But if you take a deeper look , the performance test report elaborates more information.

In this article I will use one of JMeter basic reports “Summary Report” as example to explain what I mean.

The focus in this article will be on the following terms/values

• Standard Deviation
• Min Response Time
• Max Response Time

Standard Deviation :

The Standard Deviation is a measure of how response time is spread out around the Mean. Simply say, the smaller the Standard Deviation, the more consistent the response time.

Transaction Name	RT (I1)	RT (I2)	RT (I3)	RT (I4)	RT (I5)	Avg	SD	90th %ile
Login	4	6	3	4	8	5	2	6
Search	3	2	15	1	4	5	5.7	4
Logout	5	5	6	4	5	5	0.7	5

Standard Deviation in your test tells whether the response time of a particular transaction is consistent throughout the test or not? The smaller the Standard Deviation, the more consistent transaction response time and you will be more confident about particular page/request.

Min.Response Time:

The shortest time taken by a sample for specific label. If we look at Min value for Label 1 then, out of 20 samples shortest response time one of the sample had was 584 milliseconds.

Max.Response Time:

The longest time taken by a sample for specific label. If we look at Max value for Label 1 then, out of 20 samples longest response time one of the sample had was 2867 milliseconds.

Sources :

https://www.perfmatrix.com/standard-deviation-in-performance-testing/http://www.testingjournals.com/understand-summary-report-jmeter/

Please share your tips, experience, comments, and questions for further enriching this topic of discussion.