This paper was originally authored by Greg Gendall of Midori Media and published by Project Magazine in May 2003.
It has since been revised and updated by the present author.
It was submitted for publication by Email, February 16, 2009, and is copyright © David Garland.
Published here May 2009.
Man Hours versus Time S-curve
The Man Hours versus Time S-curve is appropriate for projects that are
labor intensive. It shows cumulative man hours expended over time for the duration
of the project. As man-hours are a product of manpower and working hours, these
may be adjusted together or individually in an attempt to keep the project on
schedule. Projects may require additional man-hours to finish on time due to low
productivity, delays and disruptions, rework, variations, etc.
Figure 1: Man Hours versus Time S-curve
Costs versus Time S-curve
The Costs versus Time S-curve is appropriate for projects that contain labor
and non-labor (e.g. material supply / hire / subcontract) tasks. It shows cumulative
costs expended over time for the duration of the project, and may be used to assist
in the calculation of the project's cash flow, and cost to complete.
Figure 2: Costs versus Time S-curve