Administration Guide
1.1.2 - When Should Project Templates Be Used?

Project templates should be used for all projects in your office which have a similar structure.

A 'project copy' action should only be performed to help set up a new project template, or to create custom activity and task lists if your office performs a few large-scale projects each year. For simplicity, long-term projects which will only be referenced once in your system (such as internal records for recording in-house administration or vacation time) should be created without using a project template. All other work should reference your office's own set of project templates.