As explained in this article, you can use spaces for each of the projects your team is working on.

Once a project has ended, you can archive that space. Once you archive a space:

• New records cannot be added to that space.
• Records in that space cannot be edited.
• It is excluded from search results by default.
• It is excluded from "List of Spaces" by default.
• It is not counted against your "maximum spaces" limit - in case your Accompa edition has such a limit.