At the time of writing, I've spent the past ~5 years thinking about various pain points I've encountered when dealing with the recurring question: 'And how long do you think this is going to take?'.

Over the course of many articles, I would like to share what I've learnt about the subject, in the hopes it would help you too. Consider this article to be the main jumping-off point towards various paths I've explored. Some of these paths cross each other again later. Some of those articles will be opinionated, some of them with a basis in principle and some purely anecdotal.

Challenges regarding estimations

• Sources of inaccuracies in estimations

• Confusing estimates versus budgets, capacity versus lead time

• Why do so many sprints fail?

• When asking for estimates is the wrong question to ask

Methodologies

• Absolute time estimation

• Back-of-the-envelope and categorical estimations

• Storypoint based estimation

• #no-estimates movement and counting tickets

• Cycletime-metrics based forecasting

• Throughput-metrics based forecasting using Monte Carlo simulations