Cone of uncertainty

As more research and development is done, more information is learned about the project, and the uncertainty then tends to decrease, reaching 0% when all residual risk has been terminated or transferred.

Original research for engineering and construction in the chemical industry demonstrated that actual final costs often exceeded the earliest "base" estimate by as much as 100% (or underran by as much as 50%[2]).

This can be done with formulas applied to spreadsheets, or by using a project management tool that allows the task owner to enter a low/high ranged estimate and will then create a schedule that will include this level of uncertainty.

[6] Over the past decade, storms have traveled within their projected areas two-thirds of the time,[7] and the cones themselves have shrunk due to improvements in methodology.

It is currently working in-house on seven-day forecasts, but the resultant cone of uncertainty is so large that the possible benefits for disaster management are problematic.

They published a proposed standard estimate type classification system with uncertainty ranges in 1958[9] and presented "cone" illustrations in the industry literature at that time.

[10] Later work by Boehm and his colleagues at USC applied data from a set of software projects from the U.S. Air Force and other sources to validate the model.