Cycle time and historical forecasting
Forecasting from measurements of how long work in fact takes, instead of how long people hope it will take. It is the outside view put into operation, and history beats optimism.
Evidence grade: practice A widely adopted practitioner model with clear provenance.
Use it when
Forecasting; recalibrating people who chronically over- or under-commit; replacing estimation theatre.
Where it stops working
History predicts only work that resembles the past, so novel work still needs spikes to de-risk it. A cycle-time distribution is a range, and quoting its average as a date repeats the original error.
Where the standard uses it
- DE-2Estimation, planning, and honest commitmentsManaging uncertainty rather than chasing accuracy.
Used alongside it
- Batch size and predictability practice
- Brooks's law practice
- The cone of uncertainty practice
- The planning fallacy research
Cite this model
Chicago, BibTeX and licence →Engineering Management Academy. (2026). Cycle time and historical forecasting. In Engineering Management Academy Body of Knowledge (Version 3.1, TEC.cycle-time-and-historical-forecasting). https://www.engineeringmanagement.academy/body-of-knowledge/techniques/cycle-time-and-historical-forecasting