Part of the responsibility of being a manager is the career advancement of your direct reports, and you should always be on the lookout for signs they might be ready for the next step; though that can be easier said than done.  The article, “Who Should Get Promoted? The Ultimate Guide for Managers,” by Avery Augustine helps break down what managers can be looking for to identify promotable candidates. They are….
1. They have quantifiable success to back them up
2. They stay late to get the job done
3. They are part of the solution
4. They help out and share knowledge when they can
5. They are constantly learning
6. Feedback is welcomed and appreciated, whatever it is
7. They want to be promoted, and voice it
When it comes to promoting, one size does not fit all, but keeping an eye out for certain behaviors will clue you in as to who is ready.  Visit the article for examples of what to look for.