Too Deep Inheritance Hierarchy

Deep inheritance hierarchies can result in extremely flexible systems. Unfortunately, at the same time the system’s understandability and the adaptability of its inheritance hierarchies suffers. If inheritance takes place across 10 levels, it is almost impossible to determine which implementation of a method is called by reading the code.

Related smells: Deep Hierarchy

Reference

M. Lippert, S. Roock, “Refactoring in Large Software Projects: Performing Complex Restructurings Successfully”. John Wiley and Sons, 2006.