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.

cone of uncertainty

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

SearchCompliance

  • risk management

    Risk management is the process of identifying, assessing and controlling threats to an organization's capital and earnings.

  • compliance as a service (CaaS)

    Compliance as a Service (CaaS) is a cloud service service level agreement (SLA) that specified how a managed service provider (...

  • data protection impact assessment (DPIA)

    A data protection impact assessment (DPIA) is a process designed to help organizations determine how data processing systems, ...

SearchSecurity

  • quantum key distribution (QKD)

    Quantum key distribution (QKD) is a secure communication method for exchanging encryption keys only known between shared parties.

  • identity theft

    Identity theft, also known as identity fraud, is a crime in which an imposter obtains key pieces of personally identifiable ...

  • cybercrime

    Cybercrime is any criminal activity that involves a computer, networked device or a network.

SearchHealthIT

SearchDisasterRecovery

  • disaster recovery plan (DRP)

    A disaster recovery plan (DRP) is a documented, structured approach that describes how an organization can quickly resume work ...

  • 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 team

    A disaster recovery team is a group of individuals focused on planning, implementing, maintaining, auditing and testing an ...

SearchStorage

  • logical unit number (LUN)

    A logical unit number (LUN) is a unique identifier for designating an individual or collection of physical or virtual storage ...

  • NVMe over Fabrics (NVMe-oF)

    NVMe over Fabrics, also known as NVMe-oF and non-volatile memory express over fabrics, is a protocol specification designed to ...

  • CIFS (Common Internet File System)

    CIFS (Common Internet File System) is a protocol that gained popularity around the year 2000, as vendors worked to establish an ...

Close