Measuring object-oriented system complexity

This paper addresses Object-Oriented (OO) system complexity at the application, object, method, and variable levels. At each level measures are proposed to account for the cohesion and coupling aspects of the system. OO system complexity at each level is presented as a function of the measurable characteristics such as fan-in, fan-out, number of I/O variables, fan-up, fan-down, and polymorphism. Each measure is defined with adherence to the principles that measures must be intuitive and that they must be applicable to all phases of the OO development life cycle. I