Calculates the Efferent Coupling for a package. This is a count of the number of other packages that the classes in a package depend upon, and is an indicator of the package’s independence (). This is a package-level metric.
Implemented by the
The following properties can be configured for this metric within a MetricSet. See Creating a MetricSet for information on the syntax of setting a metric property.
|ignorePackageNames||The names of packages to ignore when calculating afferent coupling. This pattern string may contain wildcard characters (‘*’ or ‘?’); it may also contain more than one pattern, separated by commas.||null|
 “CodeQuality for Software Architects: Use coupling metrics to support your system architecture” - Andrew Glover, part of the “In pursuit of code quality” series in developerWorks. This article includes a discussion of Efferent Coupling, among other metrics.
 Code Quality: The Open Source Perspective - Diomidis Spinellis. Addison Wesley, 2006.
 Agile Software Development, Principles, Patterns, and Practices - Robert C. Martin. Prentice Hall, 2002.