Calculations in Automations

[Henk Heijmink]

Hi all, I have 3 custom fields that contain numerical values. (say a, b and c) I want to set up an automation that is fills a 4th custom field with the value of a x b x c.

The values are actually a number that represent severity, probability and easy of detection for a specific bug. The multiplication of these number a x b x c will produce a number called RPN (Risk Priority Number) that will indicate the priority to work on fixing a bug.

It's a bit silly that we have to manually doc this calculation is any of the parameters change, so I was wondering if an automation is possible to do this?

I'm not so familiar with Jira yet, so your help is appreciated.
Thanks!