The larger and more complex your plan is, the more work Jira has to do to load it. So while we’re constantly optimizing load times, the best way to speed up your plan’s performance is to keep it as focused as possible.

While loading the plan, Jira will read the data stored in your issues included in the plan. Then it runs calculations (such as capacity planning and dependencies) to generate your roadmap.

1. If you’re using a JQL query/Filter as part of your plan and you’re experiencing poor performance, make sure that the query is optimized 
2. Remove Issue sources - Plans can handle up to four issue sources with no problems. The impact of issues sources beyond this depends on their complexity. Alternatively, if you only need a handful of issues from an issue source, consider moving those issues to a different project or using exclusion rules to only pull in the relevant issues.
3. Limits on the number of issues - All plans have a soft limit of 5,000 issues. You can exceed this number, but the performance of your plan will begin to suffer. For this reason, we recommend that you remove unnecessary issues, or consider breaking larger roadmaps into two separate plans.
4. Remove issues belonging to old releases - By default, Jira adds all releases and fix versions in a project to your plan regardless of when they’re scheduled to happen. These extra releases might technically be relevant to your plan, but realistically slow down your plan’s performance. This is why we recommend that you either delete old releases in Jira or use exclusion rules to focus on issues belonging to specific releases in your plan.
5. Remove excess sprints - As mentioned previously, capacity planning calculations are done entirely in your plan when you load them. The more sprints that are included in your plan, the more effort required by plans , leading to longer load times. To remove old sprints from your plan, use the Exclude any completed issues after field in the exclusion rules, or delete old sprints from your boards in Jira.