S-Curve Project Management
The S-Curve in Project management is a form of mathematical theory, which aims to represent the utilization of resources over the proposed time of your project. The curvature illustrates the side by side comparisons of the actual expenditure components and time vs. the proposed time and costs allocations of specific resources.
An s-curve is a graphical tool that displays cumulative data ( e.g. project’s costs, quantities, hours, progress) against time. The term S-Curve denotes the tendency of the cumulative curve to form a shallow ‘S’ shape; flatter at the start, steeper in the middle, and flattening off again towards the end.
Although the s-curve drives from the S-like shape of the curve, don’t be surprised if your s-curve isn’t in the shape of an “S”. There are several shapes for S-curve which depends on the nature of the project.
Types of S-curves in Project Management
There are many several types of S-curves such as man-hours vs. time and cost vs. time. The cost vs. time S-curves is useful for developing the project’s overall “cash flow”.
Another common type of S-curves is the ones generated using units/quantities vs. time. These types of s-curves are useful for comparison.
You may find a front-loaded s-curve, where the curve starts up steeply and then flatten out.
As explained here, front-loaded curves have a quick start. More money and resources will be consumed early in the project. This may happen for repetitive projects that need little preparation time and planning. Other examples of front-loaded curves are for projects that have been accelerated from the beginning, or projects that need an urgent repair of damage early on. Deposits and Mobilization costs will also lean toward a front-loading s-curve.
Back-loaded S-Curves are the curves that start with a lower slope and increasingly steep towards the end of the project, most resources assumed to be consumed late in the project.
A backloaded s-curve could indicate large design and planning or in the beginning and reduced construction time.
- You should verify the basis of the project plan and ensure both the schedule and the available resources are realistic.
- With the understanding of s-curves and their various shapes, now the question is “what kind of information is plotted in an s-curve?”