State diagram Implementation
There is not really enough information in your question to know what kind of state machine we are talking about as the terminology is very generic.

If we are talking a sequential logic system implemented using either discrete logic or FPGAs then you might want to search for Moore Model, Meely Model or Algorithmic State Machine. All these can be implemented using a clocked state register and logic. Many hardware descriptions compile down to these kind of approaches. With a more complete description I could give better advice.