Steps

Performance Data Investigator (PDI) inside of IBM Navigator for i is a tool that can be used to tell you who may have used CPU cycles during a particular timeframe.  However, it cannot tell you WHY they were using CPU.

To explore why the CPU was high and which jobs/tasks used it we first need to open the browser interface.

Substitute your system name or IP address of your partition in the following URL: http://system:2002/Navigator/login, then, log in using your credentials. 

Once logged in, click on the system you want to look at (there can be more than one here) and the Actions icon,

Choose Manage Node.  On the next screen we want to get into the performance data.  Click on the line graph icon then select Investigate Data

This will bring up the Investigate Data screen where you can choose your library and dataset you want to review.

NOTE: In rare instances, you may not see your library in the list. If this happens, try rebuilding the collection table to resolve. You would go back to the line graph and choose Manage Collections then Collection Service collections. Click on Actions then Rebuild Collection Table. 

In this instance we are looking at CPU usage, so click the CPU Utilization and Waits Overview

You will get a graph showing the full dataset of CPU usage.

Using the scroll bars at the bottom, you can focus in on a timeframe section versus the whole graph.

To select intervals you want more information on, click on them to select them. Go to Actions Icon at the top, then CPU Utilization and Waits Overview and then CPU Utilization by Thread or Task

This brings up a graph showing what threads/tasks used CPU during the interval/s selected.

You can shrink this list down by using the scroll bar at the bottom.

Select a job by clicking on it and you can see the utilization during the life of the job by going to the CPU Utilization for Threads or Tasks option

For further information, on what the job is doing while dispatched to the CPU, collect a job watcher trace while the issue is happening: https://www.ibm.com/support/pages/node/685927

More information on PDI: https://www.ibm.com/support/pages/performance-data-investigator-navigator-i