Why are so many software projects late? Estimation (and how we use it) is often at the heart of it.

Humans are naturally optimistic. We overestimate how well things will go and underestimate the time required. It’s a well documented phenomenon:

🤞 Optimism Bias: Our tendency to believe things will go better than they likely will.

🗓️ Planning Fallacy: Underestimating time required, even when past experience tells us otherwise.

Secondly, even with careful planning, we can only account for what we know. As well as software development being inherently complex, as time progresses, unexpected factors always emerge: shifting priorities, new challenges, team changes – the “known unknowns” as Donald Rumsfeld infamously put it.

𝗖𝗮𝗻 𝘆𝗼𝘂 𝗴𝗲𝘁 𝗯𝗲𝘁𝘁𝗲𝗿 𝗮𝘁 𝗲𝘀𝘁𝗶𝗺𝗮𝘁𝗶𝗻𝗴?
Yes, we can avoid common pitfalls and improve our estimation practices. But they are still likely to be optimistic because of the reasons above.

“It always takes longer than you expect, even when you take into account Hofstadter’s Law.”

– Hofstadter’s Law


𝗗𝗼𝗲𝘀 𝗔𝗴𝗶𝗹𝗲 𝘀𝗼𝗹𝘃𝗲 𝘁𝗵𝗶𝘀?
Agile embraces uncertainty, such as breaking down work into the smallest possible pieces and delivering value early and often. But it doesn’t eliminate the challenge of longer-term planning.


𝗗𝗼𝗻’𝘁 𝗯𝗼𝘁𝗵𝗲𝗿 𝗽𝗹𝗮𝗻𝗻𝗶𝗻𝗴 𝘁𝗵𝗲𝗻?
Not at all. Organisations need to plan. Without long-term planning, you can’t set realistic budgets, allocate resources & people, or prioritise efforts. The trick is learning how to plan effectively, even in the face of uncertainty.

In my next post, I’ll share how I’ve approached longer-term planning successfully.