How to handle tracking with small releases leading up to one big release?

[swimmer20]

We have 3 projects/teams working in parallel on work that will be released in small releases over the next few months. This work and releases lead up and contribute to one bigger and major release that is Critical for the business (ie. the big critical release is dependent on all the small releases - BUT if a small release slides by a week its not as critical as long as the release the end can still be met).  What is the best way to track this so we can track the small release progress as well as the  big, critical release progress that encompasses all these mini releases along the way?  

[Anon Anon]

You can use Release field to track the Program Increments and Milestone to track the big critical release which includes the multiple releases.

[IlaPiddington1360917]

We use milestones in this scenario.  Work items for the major release all have that milestone, and then the subset of items also have the minor release milestone.