This paper presents a technique to automatically identify duplicate and near duplicate functions in a large software system. The identification technique is based on metrics extracted from the source code using the tool Datrix(. This clone identification technique uses 21 function metrics grouped into four points of comparison. Each point of comparison is used to compare functions and determine their cloning level. An ordinal scale of eight cloning levels is defined. The levels range from an exact copy to distinct functions. The metrics, the thresholds and the process used are fully described. The results of applying the clone detection technique to two telecommunication monitoring systems totaling one million lines of source code are provided as examples. The information provided by this study is useful in monitoring the maintainability of large software systems.