Number of Faults per Line of Code

In this note, the number of faults or "bugs" per line of code is estimated based upon Halstead\´s software science relationships. This number is shown to be an increasing function of the number of lines of code in a program, a result in agreement with intuition and some current theories of complexity. The form of this function is investigated and an easy-to-use approximation is developed. An application to a moderately large software project is shown in which the predicted number of faults for program modules of various sizes agrees fairly well with the actual numbers of faults discovered.