Three point estimation
A three-point estimate is a method used to estimate the cost or duration of a project task or activity. It is commonly used in project management, and it is particularly important in the construction industry, where projects can be complex and involve many different tasks
It involves using three estimates: an optimistic estimate, a most likely estimate, and a pessimistic estimate.
- The optimistic estimate is the best-case scenario for how long the task will take or how much it will cost.
- The pessimistic estimate is the worst-case scenario.
- The most likely estimate is the estimate it is believed is the most accurate representation of how long the task will take or how much it will cost based on their experience and expertise.
To calculate the three-point estimate, the three estimates are first added together and then divided by three to give an expected value. This expected value can be used to help project managers plan resources and schedule tasks more accurately.
Should cost modelling, Development Guidance, Version 1.0, published by Government Commercial Function in May 2021 states: ‘This technique uses three different estimates of potential costs, the most likely, optimistic and pessimistic profiles. These estimates are then aggregated and averaged to provide estimates that are adjusted for extremes. It is often applied in the context of Monte Carlo simulation to produce probabilistic outputs.’
[edit] Related articles on Designing Buildings
Featured articles and news
Cyber Security in the Built Environment
Protecting projects, data, and digital assets: A CIOB Academy TIS.
Managing competence in the built environment
ITFG publishes new industry guide on how to meet the ICC principles.
The UK's campaign to reduce noise pollution: Mythbusting, articles and topic guides.
Setting Expectations on Competence Management
Industry Competence Committee.
New Scottish and Welsh governments
CIOB stresses importance of construction after new parliament elections.
The sad story of Derby Hippodrome
An historic building left to decay.
ECA, JIB and JTL back Fabian Society call to invest in skills for a stronger built environment workforce.
Women's Contributions to the Built Environment.
Calls for the delayed Circular Economy Strategy
Over 50 leading businesses, trade associations and professional bodies, including CIAT, and UKGBC sign open letter.
The future workforce: culture change and skill
Under the spotlight at UK Construction Week London.
A landmark moment for postmodern heritage.
A safe energy transition – ECA launches a new Charter
Practical policy actions to speed up low carbon adoption while maintaining installation safety and competency.
Frank Duffy: Researcher and Practitioner
Reflections on achievements and relevance to the wider research and practice communities.
The 2026 Compliance Landscape: Fire doors
Why 'Business as Usual' is a Liability.
Cutting construction carbon footprint by caring for soil
Is construction neglecting one of the planet’s most powerful carbon stores and one of our greatest natural climate allies.