When a grievance is unresolved even after presenting it to the industrial representative, the parties submit the dispute to a(n) who hears evidence from both sides and renders an award?

A grievance that can not be resolved through the normal grievance process it moves to arbitration. In this process the parties appeal to a third party arbitrator who is empowered to make a decision binding on both parties. In most industrial cases, the arbitrator is randomly chosen from a list agreed upon by both parties. One benefit of deferring to an arbitrator is that it is less costly that resolving disputes through the judicial system.