Planning fallacy
Ошибка планирования · Иллюзия планирования
We chronically underestimate how long things will take, how much they will cost, and how much can go wrong.
When we plan from inside the project, we imagine the smooth path. We do not vividly imagine the four unrelated emergencies, the dependency that gets delayed, the team member who leaves. The reference class of similar projects always knows better than our inside view.
Almost every promise you make to yourself or others contains a planning fallacy. Correcting it is one of the cheapest, highest-leverage shifts in decision quality.
«Two weeks» becomes three months. Renovations finish at 2× budget. Books get written in 4× the time. Every. Time.
- 1Build an outside view: find 5+ similar past projects, compute the median time/cost overrun, apply that multiplier.
- 2Add a buffer for the unknown unknowns: «what would the worst quarter look like?»
- 3Pre-commit to a check-in date when reality will be checked against the plan.
This part of the knowledge base is inspired by the book. Go to the Ukrainian edition to explore the concept in depth.
- · Методичка по Канеману - ошибка планирования