Browse Definitions :
Definition

cone of uncertainty

Contributor(s): Matthew Haughn

The cone of uncertainty is a graphic depiction of the increasing accuracy that is possible for estimates as the details of a project become more known over time. Project managers and developers use the cone of uncertainty to guide estimates manage expectations.

During the development process a project starts out with a large degree of variability. An estimate may be accurate but that cannot be assumed. Generally, any estimates will be very loose and may be wildly inaccurate. As decisions are made, research is conducted and more of the project is completed, the degree of variability decreases. This is why project might start out with estimates varying by plus or minus 40 percent at the start but see that variance decrease over time. Understanding this variability is key to developing realistic project plans. 

The most common representation of the cone of uncertainty is in the form of a graph with time on the horizontal axis and estimate variance on the vertical. As the graph is followed to the right with the progress of time, the lines representing the range of overestimation converge to near zero. The large end of the cone – where uncertainty is greatest – is at the start of the project timeline and the small end of the cone at the end, where all details are known.

The cone of uncertainty was originally created by the American Association of Cost Engineers to assist estimations for engineering and construction. The tool is applied to a variety of phenomena such as hurricanes, for example, in which the system’s course is less certain when predicted further into the future and more certain as time goes on and the system gets closer.

This was last updated in March 2015

Continue Reading About cone of uncertainty

Start the conversation

Send me notifications when other members comment.

Please create a username to comment.

-ADS BY GOOGLE

File Extensions and File Formats

Powered by:

SearchCompliance

  • compliance framework

    A compliance framework is a structured set of guidelines that details an organization's processes for maintaining accordance with...

  • regulatory compliance

    Regulatory compliance is an organization's adherence to laws, regulations, guidelines and specifications relevant to its business...

  • privacy compliance

    Privacy compliance is a company's accordance with established personal information protection guidelines, specifications or ...

SearchSecurity

SearchHealthIT

  • telemedicine (telehealth)

    Telemedicine is the remote delivery of healthcare services, such as health assessments or consultations, over the ...

  • Project Nightingale

    Project Nightingale is a controversial partnership between Google and Ascension, the second largest health system in the United ...

  • medical practice management (MPM) software

    Medical practice management (MPM) software is a collection of computerized services used by healthcare professionals and ...

SearchDisasterRecovery

  • disaster recovery (DR) test

    A disaster recovery test (DR test) is the examination of each step in a disaster recovery plan as outlined in an organization's ...

  • business continuity plan (BCP)

    A business continuity plan (BCP) is a document that consists of the critical information an organization needs to continue ...

  • disaster recovery (DR)

    Disaster recovery (DR) is an area of security planning that aims to protect an organization from the effects of significant ...

SearchStorage

  • kilobyte (KB or Kbyte)

    A kilobyte (KB or Kbyte) is a unit of measurement for computer memory or data storage used by mathematics and computer science ...

  • megabytes per second (MBps)

    Megabytes per second (MBps) is a unit of measurement for data transfer speed to and from a computer storage device.

  • zettabyte

    A zettabyte is a unit of measurement used by technology professionals and the general public to describe a computer or other ...

Close