This document discusses upgrading Team Foundation Server. It describes the different types of upgrades including in-place, migration-based, and consolidation upgrades. It provides details on the upgrade process such as verifying system requirements, backing up data, upgrading SQL Server, and installing the new version of TFS. It also covers considerations for the upgrade like how process templates, reports, and the data warehouse are handled as well as recommendations to backup and test the restore before performing the upgrade.