Source: https://www.quantsurv.com/library/definitions/critical-path
Content format: Markdown version of the public page.
Content reviewed: 2026-10-12

# Critical path

The sequence of activities that determines the earliest completion of the work or milestone being analysed, using the programme’s logic, durations and constraints.

by [Jack Butler-Kettle](<https://www.quantsurv.com/about#jack-butler-kettle>) · About 1 min readShare

## Further detail

Read this alongside [SCL Delay and Disruption Protocol](<https://www.scl.org.uk/sites/default/files/documents/SCL_Delay_Protocol_2nd_Edition_Final.pdf>).

A critical-path assessment explains which activities control the completion being tested. The result depends on reliable logic, durations, calendars, constraints and recorded progress. A coloured bar in a programme is not enough to establish why completion moved. Critical activities may change as work progresses, and more than one path may be critical.

Identify the programme version and progress date, then test the event against the activities and milestone it affects. Keep the programme and actual records together. The [delay and disruption comparison](<https://www.quantsurv.com/library/delay-and-disruption>) distinguishes time effects from productivity and cost effects. For the commercial cost consequences of a programme event, [Delay and disruption cost recovery](<https://www.quantsurv.com/claims?service=%2Fdelay-and-disruption%2Fservices%2Fdelay-disruption-recovery#client-types>) connects the claimed loss to supporting records and the applicable contract.

## Sources

1.  [Delay and Disruption Protocol, 2nd edition, February 2017](<https://www.scl.org.uk/sites/default/files/documents/SCL_Delay_Protocol_2nd_Edition_Final.pdf>). Society of Construction Law.

[Browse the Library](<https://www.quantsurv.com/library>)