A Roll-Up summary field may be used to store the number of JIRA issues associated with a Case.  This count is derived from the junction object ZIssue_Case since this has a master-detail relation with Case. Note that the same field can be defined for other Salesforce Objects.

  • Define new field as Roll-Up Summary as shown below 
  • Assign the field to Salesforce Profiles, Layouts and Save

The Jira_Issues roll-up summary field can be included on Case List Views, Reports, etc.