Any way to change the format of the duration to something easier for calculation

= hour(process_duration())*60*60 + minute(process_duration()) * 60 + second(process_duration()) will convert the duration to seconds

Change the Process Duration column with the above expression rule definition in the report, then save the report.

Expression provided by Chetan is good, one thing is missing days to seconds conversion, I modified his expression to add day to seconds conversion - =tointeger(process_duration())*60*60*24 + hour(process_duration())*60*60 + minute(process_duration()) * 60 + second(process_duration())

In addition to the previous comments, it might be useful to create an external expression rule that will take the time value and return the number of seconds, which could be used elsewhere and also debugged without needing to edit the process report multiple times. Note that when calling an expression rule from the process report definition field, the system seems to dislike when the rule contains functions that use dictionary syntax, so keep that in mind while designing if you take this approach.

@Sanjeev, thank you for correcting. @mschmitt, yes it is good to create an external rule.

Thank you everyone!