Write a discussion paper on Why contracts are required?

Definition: Contract Administration is to assure; The Contractor’s performance AND the Employers performance are in accordance with ALL of the terms and conditions of the contractual agreWrite a discussion paper on Why contracts are required?
With Contract;
1- Specify time, cost and quality of what is required.
2- Defines terms and conditions for what is being delivered.
3- Risk is distributed amongst the parties.
4- And all other requirements are defined.
Without Contract;
1- Multiple Interpretations for time, cost and quality.
2- No definition of terms and conditions.
3- No definition of who owns which risk.