In my experience formalizing "learning" in the work place doesn't work because it requires the performance of learning for management types rather than real learning which involves working through real new problems over an extended period of time.
The real way to get employees to learn is to hand them responsibilities they are not fully prepared for along with the pay that goes with them and see how it goes. Right or wrong managers are rarely comfortable doing that.
Employees need to be comfortable failing in front of you and few are because there are few good examples of that turning out well. When it does go well, all too often the raise they were promised doesn't come through.
this isn't to say you're a poor manager, just that it's unusual to have a healthy environment for on the job learning.