Software Architect's Handbook

Increasing competence sets

The competence set for a given component in a software system determines what states and conditions it can handle. A component's level of fault tolerance and the cases that it is designed to handle depend on the collection of logic that make up its competence set. A component can be modified so that it handles more cases, reducing the exceptions that are thrown.

For example, if a method does not handle a null value for a particular parameter, an exception may be thrown, leading to a system failure. The code could be modified to handle null values, increasing the competence set of the software and preventing a fault.