Analysis of Labor Relations Contracts

When considering labor relations and working from the union side of a contract, what are some of the advantages to having a long contract (5 years) versuses a shorter contract? How will having a long contract save the company money? What are some ways the company can promote incentives to the union labor force when negotiations are underway? Should the union cap the quantity of work on a shift, i.e. Auto industry cap how many cars are made in one day, to help improve quality?