Man-hour

Man-hours exclude the breaks that people generally require from work, e.g. for rest, eating, and other bodily functions.

This adage is often cited in systems development to justify the belief that adding more staff to a project does not guarantee it will get done quicker.

Another problem with this model, as Fred Brooks noted, is that organization, training, and co-ordination activities could more than outweigh the potential benefits of adding extra staff to work on a task, especially if considered only over a shorter time period.

It is the amount of work performed by an average worker during one day, week, month, or year, respectively.

The number of hours worked by an individual during a year varies greatly according to cultural norms and economics.

[5] The concept of productive system hours (PSH) has been used in forestry in Austria and by extension to other work.