
456 ◾ Software Metrics
Inglis describes a set of “standard soware quality measures used at
AT&T Bell Laboratories,” all of which are derived from defects data col-
lection (Inglis 1985):
• Cumulative fault density—faults found internally
• Cumulative fault density—faults found by customers
• Total serious faults found
• Mean time to close serious faults
• Total eld xes
• High-level design review errors per thousand NCLOC
• Low-level design errors per thousand NCLOC
• Code inspection errors per inspected thousand NCLOC
• Development test and integration errors found per thousand NCLOC
• System test problems found per developed thousand ...