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

Powered by:

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

  • spyware

    Spyware is a type of malicious software -- or malware -- that is installed on a computing device without the end user's knowledge.

  • application whitelisting

    Application whitelisting is the practice of specifying an index of approved software applications or executable files that are ...

  • botnet

    A botnet is a collection of internet-connected devices, which may include PCs, servers, mobile devices and internet of things ...

SearchHealthIT

SearchDisasterRecovery

  • 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 ...

  • cloud insurance

    Cloud insurance is any type of financial or data protection obtained by a cloud service provider. 

SearchStorage

  • DRAM (dynamic random access memory)

    Dynamic random access memory (DRAM) is a type of semiconductor memory that is typically used for the data or program code needed ...

  • RAID 10 (RAID 1+0)

    RAID 10, also known as RAID 1+0, is a RAID configuration that combines disk mirroring and disk striping to protect data.

  • PCIe SSD (PCIe solid-state drive)

    A PCIe SSD (PCIe solid-state drive) is a high-speed expansion card that attaches a computer to its peripherals.

Close