What is an S-curve
An S-curve is a mathematical graph in project management that represents relevant cumulative data for a project, such as cost or man-hours, plotted against time. The shape of the graph often forms a loose, shallow "S," thus the name "s-curve." In project management, an s-curve is commonly used to track the progress of a project. In today's fast-paced corporate environment, keeping a project on time and on budget is critical to its success.
Because project development is typically modest in the early phases, the s-curve frequently takes shape. The wheels are just starting to revolve; team members are either researching the industry or engaging in the initial phase of implementation, which can be stagnant while working out the problems.
Below image is an example of S-curve graph -
As progress is achieved, the rate of growth accelerates, forming the upward slope that forms the center half of the "s." The maximal point of growth is referred to as the point of inflection. During this time, project team members are putting in a lot of effort on the project, and many of the big expenses are incurred.
The growth continues to plateau beyond the point of inflection, generating the top half of the "s" known as the upper asymptote—and the "mature" phase of the project. This is because the project is nearing completion and is winding down – normally, just finishing touches and final approvals are remaining at this stage.
Common Uses
S-curves are commonly used to track progress, evaluate performance, and estimate cash flows.
An s-curve is useful for tracking project progress since real-time cumulative data of various project variables, such as cost, can be compared to planned data. The degree of alignment between the two graphs reflects the development of the element under consideration. If modifications are required to get back on track, the s-curve might assist in identifying them.
S-curves can be used for a variety of purposes during the life of a project. The following are some of the most important applications of s-curves:
Performance and Progress Assessment
Cash Flow Predictions
Comparison of Quantity Output
Types of S-Curve
The s-curve can be of different types, such as:
Baseline S-curve - This s-curve depicts the expected development of the project. A baseline s-curve is the s-curve drawn from the schedule.
Target S-curve - After the project begins, changes to the baseline schedule are common. The amended schedule is referred to as the production schedule, and the production schedule is the same as the baseline schedule at first, but it varies as the project continues. The production schedule reflects the project's actual progress and can be used to generate a target s-curve.
Costs Vs Time S-curve - The costs vs. time s-curve is useful for projects that incorporate both labor and non-labor expenditures such as subcontracting, hiring, and material supply. It displays the overall cost incurred during the project's life cycle and may be used to determine project cost and cash flow.
Value S-curve - Value s-curves can be used to compute the number of man-hours or dollars spent thus far, as well as the number of man-hours or dollars required to complete the project.
Percentage S-curve - Percentage s-curves can be used to examine the planned vs. actual completion of a project, as well as the project's percentage growth, contraction, and so on.
Man-Hours versus Time S-curve - The man-hours vs. time s-curve is appropriate for labor-intensive projects since it displays the amount of man-hours spent on the project over time. The man-hours are the sum of the personnel required and the number of hours required to complete the work.
Actual S-curve - The production schedule is continuously altered during the project's lifespan. These updates provide the completed work's data, which may be used to create an actual s-curve. This s-curve depicts real progress, but it may be compared to the intended baseline s-curve to assess performance.
Project example where S-curve can be used -
For an example, the progress of construction of a commercial building can be summarized in S-curve, but we will certainly have individual S-curves for tracking various activities.
As a construction project manager, you must ensure that the project is completed on time and within budget. You must have complete control over the project's timing and budget in order to do this. Strong control over a project requires clear visibility of how the project is progressing and where it is headed.
A construction manager can use an S Curve report to keep track of -
Actual progress timeline versus planned schedule
Actual costs in comparison to budgeted costs
Actual expenses against actual progress - this is a productivity metric.
Based on the project schedule, a projected S Curve can be produced before the project begins. First, a timeline is created for each project activity. This shows the activity's cumulative progress over time. The progress of all actions is then evaluated as a weighted average versus the timeline. A planned S Curve is formed when these cumulative progress numbers are plotted as a curve against time.
When the project begins, you may create an S Curve for real project progress using actual cumulative progress data rather than projected progress. The green curve in the illustration above represents it.
When work on the project begins, the construction crew sends in progress updates. This progress information is updated in a S Curve report.
So, at any moment, you may access the S Curve report to learn where your construction project is in terms of progress, expenses, and productivity (or profitability).
This provides you with real-time visibility into how your project is progressing and where it is heading. You will then have complete control over those projects.