Lawyers will tell you that a formal contract is needed to protect you when your rosy honeymoon with your business partner is over. Businessmen will reply that it's all about the relationship.
The different points of view will be tested when one party to a contract wants it renegotiated because of changed circumstances or because it didn't reflect what was intended. Is a deal, a deal fixed in concrete or should it be renegotiated?
Jeswald Salacuse's You Cut a Bad Deal. Now What? analyses the dynamics of renegotiating an existing agreement. He makes a number of suggestions of what to do before the deal breaks down including one that renegotiation be specifically provided for:
Rather than viewing a long-term transaction as frozen in the detailed provisions of a lengthy document, try viewing the deal organically, as a continuing negotiation in which you seek to adjust your relationship with the other side to your rapidly changing work environment. Accordingly, your long-term contract might provide that at specified times or upon specified events, you will renegotiate or at least review certain provisions. Through this approach, you confront the problem of contract violations in advance and establish a clear framework for renegotiation.
If the deal does break down, Salacuse argues "Weigh your claim against the value of the relationship":
Willingness to renegotiate a contract typically corresponds to the value one side attaches to a potential future relationship with the other side. If the relationship is worth more than your claim for breach of contract, you ordinarily will be willing to engage in renegotiation. If, on the other hand, you conclude that your claim is worth more than the benefits from a continuing relationship, you may insist on your contractual rights to the point of resorting to litigation.
You may not be able to accurately evaluate the worth of a claim or the value of a renegotiated contract without first engaging in discussions with the other side. Moreover, satisfaction of a claim through litigation is almost always a lengthy and expensive process, a further motivation for choosing to renegotiate.