This upgrade document gives detailed step by step procedure for the In-Place upgrade from TFS 2013 to 2015 RTM with Reporting and SharePoint.
Environment Details:
TFS 2013 environment
Windows server 2012 R2, TFS 2013 update 5, SQL 2014 SP1, SharePoint 2013 SP1
TFS 2015 environment
Windows server 2012 R2, TFS 2015 RTM, SQL 2014 SP1, SharePoint 2013 SP1
Permission Requirements:
The Account running the upgrade needs to have the following permissions.
– Local Administrator on the Application Tier.
– SysAdmin on SQL Data Tier. Local Administrator on Reporting Tier as well.
– SharePoint Farm Administrator.
Upgrade process:
As this will be an in-place upgrade to TFS 2015 from TFS 2013. The requirement for operating system, SQL server and SharePoint remains same for both the versions of TFS. You can find MSDN documentation here for requirement and compatibility.
Back up all the databases from TFS 2013, it’s recommended to take database backup before proceeding with the upgrade.
Following are the screens of the installation process,
Step 1: Installing binaries.
As we can see in Programs and Features, TFS 2013 update 5 is installed.
When you click on the tfs_server.exe file, it will start installing binaries required on to the server and in the same process it will also uninstall previous version from server (in our case TFS 2013).
In this process TFS 2013 binaries will be removed but the databases are untouched.
As we can see now, TFS 2013 is uninstalled and TFS 2015 is installed.
The TFS installation wizard will complete and automatically point it to the TFS upgrade wizard.
Step 2: Specifying TFS configuration database.
We need to point to our existing SQL Server which host TFS 2013 databases (this should get populated automatically)
Note: It would only list the configuration database and not all the collection databases. Configuration database holds the information for other collection databases.
Note: check the box by confirming that you have taken backup.
Step 3: Selecting TFS service account
Provide the service account. Service account can be system account or user account.
(it should already show our TFS 2013 service account which was in use before the upgrade process, if you want you can change the service account also)
Step 4: File cache folder
Set the file cache folder path. By default, path will be set but you can change the same.
Step 5: Selecting Build service account
If build is configured, provide the service account and click next.
Step 7: Configuring Reporting
Select the checkbox to configure reporting services.
Step 8: Providing settings for Reporting services
Populate the URL for reporting service configuration and validate the URL by browsing to the URL on a browser.
Step 9: Specifying Warehouse Database:
Click on List Available Databases hyperlink. Select the valid Warehouse database and click next.
Step 10: Setting Analysis instance.
Enter analysis instance name and proceed.
Step 11: Setting account for reports.
You can provide separate reader account for reports or ignore the screen and proceed. (Ignoring it would use the same account for TFS Reports as TFS Services which we have set earlier) If you had used Network Service as TFS Service account then we have to specify a different account here as we cannot use Network Service as TFS Reports Reader account.
Step 12: Setting for SharePoint.
Select the checkbox to integrate with SharePoint. Select default setting and proceed.
Step 13: Confirming settings
Confirm the setting before proceeding to next step.
Step 14: Readiness check.
The verification process identifies errors and warnings. These errors should be fixed before proceeding further. 
(The warning in this scenario can be ignored as it is complaining to use different account for reports)
Step 15: Configuring the update.
This step will configure the Application Tier and start the upgrade of Project Collection(s) in the background. Proceed with next to monitor the collection upgrade..
Step 16: Finishing upgrade
Once the upgrade succeeds, click next and close. This will automatically open Team Foundation Administration Console.
Note: In case you did not have Reports or SharePoint configured earlier, then those options would be disabled for you and we cannot enable it during this upgrade. But you can opt out of Reports/SharePoint during upgrade. That means if you had Reports enabled in TFS 2013 environment and you wish not to use Reports in TFS 2015 then you can check Reports option out, same goes for SharePoint.
That’s it, you have a brand new TFS 2015 setup from 2013 with exciting new features!
Content Created By : Ramandeep Singh
Content Reviewed By : Romit Gulati