Rule Definition
Depth is generally better than breadth in class hierarchy, since it promotes reuse of methods through inheritance.
NOC measures the potential influence a Class has on the design. Classes with large number of children require more intensive testing as through inheritance an implementation error can potentially lead to many regression bugs.
Technical or framework classes which are evolving and will not be changed often should not be concerned by this rule.
Remediation
Review the design of Class hierarchy
Reference
A Metrics Suite for Object Oriented Design
Chidamber, S.R. and C.F. Kemerer
IEEE Transactions on Software Engineering, 1994
Related Technologies
Technical Criterion
Complexity - OO Inheritance and Polymorphism
About CAST Appmarq
CAST Appmarq is by far the biggest repository of data about real IT systems. It's built on thousands of analyzed applications, made of 35 different technologies, by over 300 business organizations across major verticals. It provides IT Leaders with factual key analytics to let them know if their applications are on track.