Ensure that you do a post-mortem (or even a minimum introspection) at every milestone

Not every team goes in for something like Scrum; there are some problems with Scrum implementation, especially when you need to plan across multiple Sprint cycles. So, teams will stick to their existing methods of development, such as Waterfall or Incremental / Iterative modes of development.
However, for ensuring that your software development cycle is as effective as it can be, you should ensure that you are getting frequent updates from your team. If you are the project manager / program manager of the team, or the developer or QE manager, it is required that you should set up periodic post-mortems for the team.
Collecting feedback from the team members is an important part of the overall way to help your processes become more efficient and effective. From your location, everything may seem to be fine, but unless you talk to the people in the trenches, you will never find out whether there are issues that are under the radar, or if there are improvements that can be made in the existing processes.
Also, if you hold periodic sessions of introspection and show action, then it makes the team feel that their thoughts and feedback is being incorporated, and they also start thinking in terms of how to improve the overall functioning of the team.