Rule Definition
Excessive coupling between objects is detrimental to modular design and prevents reuse. The larger the number of couples, the higher the sensitivity to changes in other parts of the design and therefore the more difficult the maintenance.

Remediation
High CBO numbers might indicate that a class has too many responsibilities. Such a class is potential candidate for a refactoring where the class would delegate some the responsibilities to other classes or new classes (Extract Class, Extract Method refactoring). This will increase modularity and reusability. When refactoring with architecture in mind, the CBO metric can be used to check classes running on the application client that have high coupling. These classes are then good candidate for a refactoring towards the Session Facade pattern: http://java.sun.com/blueprints/patterns/SessionFacade.html

A Metrics Suite for Object Oriented Design Chidamber, S.R. and C.F. Kemerer IEEE Transactions on Software Engineering, 1994