Analyze trends

In the Trends page, you can view a list of all the trends defined in the system.

Overview

Defining trends enables you to compare performance test run data (transactions and web resources) over several instances of a test run. This provides better visibility of your application's performance and enables you to identify improvements or regressions in performance. For each trend in the list, summary information is displayed, providing a high-level overview of the trend.

Methods of comparison

There are two methods of comparing test run measurements for identifying performance trends. You can either compare to previous, or select a run as the baseline. By comparing the same measurement in more than one instance of a test run, you can identify whether its performance trend is improving or regressing

Method	Description
Compare to Baseline	You select one performance test run and define it as the baseline. All measurements in the report are then compared to the measurements contained in the baseline.
Compare to Previous	All measurements in a performance test are compared to the measurements in the performance test run that immediately precedes it.

Method

Description

Compare to Baseline

You select one performance test run and define it as the baseline. All measurements in the report are then compared to the measurements contained in the baseline.

comparison of measurements to baseline.

Compare to Previous

All measurements in a performance test are compared to the measurements in the performance test run that immediately precedes it.

Method of comparing run measurements of one run to previous run.

Note: The two comparison methods can yield substantially different results.
As shown in the table below, the average Transaction Response Time measurement is being trended from four performance test runs: 3, 4, 5, and 6.

Transaction Response Time (Compare to baseline)

Name	Type	Average run 3 [Base]	Average run 4	Average run 5	Average run 6
All	TRT	4.567	1.22 (-73.29%)	2.32 (-49.2%)	12.455 (+172.72%)
TRX_01	TRT	2.045	4.073 (+99.17%)	2.035 (-0.49%)	1.05 (-48.66%)
TRX_02	TRT	1.045	2.07 (+98.09%)	1.015 (-2.87%)	1.051 (+0.57%)
TRX_03	TRT	3.053	3.067 (+0.46%)	2.009 (-34.2%)	2.654 (-13.07%)
TRX_04	TRT	6.055	6.868 (+13.43%)	5.011 (-17.24%)	7.05 (+16.43%)

Run 3 has been defined as the baseline. The average transaction response times contained in the other performance test runs are compared to run 3 only.

In run 3, the average transaction response time for TRX_01 was 2.045. The average transaction response time for the same transaction in run 5 was 2.035, representing a slightly faster response time and therefore a slight improvement in the performance of this measurement. The percentage difference between the two figures is displayed in brackets, in this case -0.49%.

However, if the Compare to Previous comparison method was selected, then the average transaction response time in run 5 would run be compared to run 4 (because 4 precedes it in the table), and not to run 3. The value for run 4 is 4.073, while for run 5 it is 2.035, a percentage difference of -50.04%.

Transaction Response Time (Compare to previous run)

Name	Type	Average run 3 [Base]	Average run 4	Average run 5	Average run 6
All	TRT	4.567	1.22 (-73,29%)	2.3 (+90.16%)	12.455 (+436.85%)
TRX_01	TRT	2.045	4.073 (+99.17%)	2.035 (-50.04%)	1.05 (-48.4%)
TRX_02	TRT	1.045	2.07 (+98.09%)	1.015 (-50.97%)	1.051 (+3.55%)
TRX_03	TRT	3.053	3.067 (+0.46%)	2.009 (-34.5%)	2.654 (+32.11%)
TRX_04	TRT	6.055	6.868 (+13.43%)	5.011 (-27.04%)	7.05 (+40.69%)

Using exactly the same data, the two comparison methods yield different results. Only a slight improvement with the Compare to Baseline method (-0.49%), while a more significant improvement with the Compare to Previous method (-50.04%).

Add a new trend

You can create a new trend to view changes in performance test run data over time. For details, see Trend reports.

Next steps:

View the dashboard