Tyler,
It depends on what you expect an "archive" to be. Several years ago we faced an identical scenario. We used a rolling planning package approach wherein tasks several months in the future were entering into the plan as planning packages. They had a general
description, expected budget and expected manpower loading. As we got closer to those tasks, they were expanded in detail working tasks with the previous planning package line being the summary line. As time progressed, completed tasks in the past became historical
"bulk" that made the file larger in size and harder to maintain. To reduce the file bulk and size we a process that looked at each summary line that was 100% complete (i.e. all subtasks complete). We then created a new task line at the same level as the summary
and replicated the essential data of the summary line (i.e. start, finish, cost, resources, baseline data fields, etc.). We then deleted the summary line that was 100% complete and that of course deleted all subtasks under it. It is important to note that
any links from subtasks under that summary line had to be analyzed to insure deletion did not "telegraph" through the remaining active schedule tasks. The whole process was automated with VBA.
So we really had a two pronged approach to keeping file size manageable. Future parts of the project that were not fully defined, (this was an engineering development program), were held as planning packages until they were needed. Past tasks that were
completed were consolidated into historical tasks. And just for reference, this process was developed and maintained under a formal, certified customer approved earned value management system.
Project 2010 did introduce the ability to inactivate tasks, but that does noting to reduce the file bulk.
Anyway, this is the method I've used very successfully. Others may have equally effective approaches.
Hope this helps.
John