To visualise SLA overdue statistics add a gadget to JIRA dashboard:
Add value in the field:
- Title - a title of this gadget;
- Project or Saved (Filter) - Project or saved filter to use as the basis for the graph;
- SLA field - choose SLA field;
- Metric - choose a metric
- Group period - choose a period;
- Period type - choose a current period.
You can configure it to show only overdue SLA or SLA on time, or both of them as well.