As Sela Group continues to move hundreds of customers from Quality Center to TFS we have
upgrade our migration tool called – Scrat to support migration to TFS 2012 RC.
The migration process is Easy, Fast and doesn't required any special customization it’s just a simple wizard application that will allow you to migrate everything from Quality Center to TFS.
Requirements, Bugs, Test Cases, Attachments, Links between items and more.
Just download the trial version and follow my steps:
Step 1: Define Migration Plan
After installing Scrat the first page will ask you for two things, a configuration file that will save all completed items and migration settings and the second is defining what items would you like to migrate from Quality Center to TFS (Requirements, Bugs and Test Cases).
The configuration file will also allow you to repeat the migration process for Failed items and will skip the work items that previously migrate successfully.

Step 2: Connecting Quality Center and TFS
The connections page will ask you to connect to a specific Team Project under TFS 2010 or 2012 and connect to specific Project in Quality Center.

Step 3: User Mapping
Quality Center allow users to work without LDAP users this means that we need to create a mapping between Quality Center users to TFS Users, you will use this page to define which user from Quality Center will be translate to LDAP user in TFS.

Step 4: Area Mapping
Area Mapping is one of the important steps in Scrat, Areas will allow you to keep Quality Center folders hierarchy as Areas in TFS.
At the picture below you can see Scrat presenting the folders hierarchy, you can also modify and add new values before creating those areas in TFS.

After Scrat will finish Area creation you will see the same folders hierarchy in TFS but as Areas.

Step 5: Fields Mapping
In this steps you’ll map Quality Center fields to TFS Fields, this page will show also Customize fields in Quality Center and TFS.
Fields that you’ll not choose will not be copied during the migration.

Step 6: Data Mapping
After you choose fields for the migration you might have to define new values for those fields, it’s more than possible that the field values will be different from Quality Center and TFS.
You can also prepare for the migration by defining the proper values and fields before you start migrating.

Step 7: State Mapping
Just before you’ll start the migration we need to define one more thing, the States.
As you know TFS doesn't allow you to open Work Item and change the State field to any field that you like, you have to save the work item and than change the state again, furthermore State field in TFS works on Work Flow mechanism that force the user to work based on the state flow.
This means that we also need to define the flow for each state from Quality Center.

Step 8: Migration
In this page all you need to to is click “Start” to begin the migration, but you can also choose to migrate based on a specific filter, expend the advanced option and choose as many fields as you like to help you filtering the items for the migration.

When the migration is completed you can see those items in TFS:

Step 9: Test Suites Hierarchy – Just for Test Cases
The migration process is the same for all items except Test Case, there you will have additional Page allowing you to build the Test Suites hierarchy for Microsoft Test Manager.
First you need to create a plan or select an existing one, this will create new Test Plan in Microsoft Test Manager.

Then select the desire Test Suites to create(you don’t need to create all just those you want) and click start.

After the process is done you can enter Microsoft Test Manager and you’ll see the same Suites hierarchy as in Quality Center, and each suite has his Test Cases assigned to it.

Test Case after the migration:

Enjoy.