The Problem with “Man Hours”

I’ve never been comfortable with the concept of “Man Hours,” not that it’s a gender issue, but rather it implies ignorance of how time is used in the work place and fumbles away some simple management concepts needed to run any business, namely accountability and commitment. Actually, I thought the “Man Hour” concept disappeared with the passing of the 20th century, but it appears to be making a comeback.

The fallacy of the “Man Hour” concept is that it assumes a person is working productively 100% of the time. This, of course, is hardly the case in any company. Workers are either working on their assignments, be they what they may, or there are interferences keeping them from their work, such as meetings, phone calls, e-mails, reading, breaks, etc. Time spent on work assignments is referred to as “Direct,” and time spent on interferences is referred to as “Indirect.” The relationship of Direct to Indirect time is referred to as an “Effectiveness Rate” delineating the use of time during the work day. For example, in an office environment, 5.6 hours are typically spent on Direct work, and 2.4 hours are typically spent on Indirect interferences (assuming an eight hour business day), or an Effectiveness Rate of approximately 70%. In no way should Effectiveness Rate be confused as an efficiency rating; the two are NOT synonymous. Whereas an efficiency rating measures how well someone performs a task in a given time, Effectiveness Rate simply measures the use of time during the work day. (more…)