An Action Plan Template becomes immutable after it is published. Salesforce explicitly states that published Action Plan Templates cannot be edited or returned to Draft status.

This behavior protects the integrity of repeatable operational processes. Existing Action Plans may already have been generated from the template, and allowing administrators to alter the underlying published definition could create inconsistent inspection requirements between records created at different times. When inspection requirements change, the administrator should use the supported versioning approach: deactivate the published template if necessary, clone it to create a new template/version, modify the cloned Draft version, add or revise its tasks, checklist items, assessment content, or other configuration, and then publish the new version. Salesforce documents this same approach for application requirements and other Action Plan implementations. The absence of an Edit button is therefore expected behavior and is not resolved by adding the action to a page layout or granting additional permissions. Salesforce Support is also not required to modify the template. The same design principle applies broadly across Action Plans: all required content should be finalized before publication because the published template is treated as the controlled definition of the repeatable process.

Study Guide References: Action Plan Templates; Template Lifecycle; Draft and Published Status; Cloning Templates; Inspection Action Plans; Version Management.