I recently supported a transition effort from a production environment to the product support team. In addition to transferring the functions themselves here are a couple other items required to execute the functions:
Supporting data- Specifications, test data, and anything else needed to define the product so that the new team had a full configuration definition, and the background information to evaluate problems or proposed changes. This could be digital files, boxes of notebooks, physical test articles, or whatever the receiving organization would need to house somewhere if not in a shared system.
Unique processes and tools: Some functions developed their own applications which might be on a specific PC, or their own methods developed specifically for their function.
Knowledge transfer - In some cases there might be training required for unique processes, or tools. Prior to handing over the work, the receiving org. needs a knowledge transfer plan so they are ready to perform the function. Saving Changes...