Information Metrics: Keeping Your Writing Projects On Track 
Keeping information metrics for documentation projects gives managers the ability to more accurately estimate future projects. Publications departments can develop their own tools or they can use existing tools to track such things as page size, hours-per-page spent writing, illustrating, editing, and producing manuals; and the dependencies of each manual. This kind of information can help to determine development schedules, show how late changes affect the documentation process, and accurately determine what it will take to complete quality documentation on time and within budget.
Gordon, Judy L. STC Proceedings (1993). Articles>Documentation>Project Management>Methods