Do you underpromise and overdeliver?
We’ve all experienced that awkward silence in a Sprint Review when the boss joins the call, expecting features to be done... and they’re not. Maybe the requirements weren’t clear, maybe a "quick fix" exploded into days of debugging. Whatever the cause, the result is the same: another commitment missed, and another dent in trust.
When teams consistently overcommit and underdeliver, it breaks confidence with clients and stakeholders. Trust is hard-earned and easily lost, especially in high-budget, high-pressure environments.
The planning fallacy is real
Humans are naturally optimistic when estimating how long tasks will take. This is known as the planning fallacy. We consistently underestimate our own work by 20–50%, and the more complex the task, the worse we get.
What’s interesting is we’re better at estimating how long others will take. This means we often set unrealistic expectations for ourselves.
Why underpromising works
Underpromising and overdelivering flips this dynamic. Instead of making excuses later, you can:
- Build trust with consistent, reliable delivery
- Create positive surprises that strengthen client relationships
- Give your team breathing room for the inevitable unknowns
"I thought this would only take a day... but it turned into three days of debugging."
Figure: Bad example – Being overly optimistic leads to missed deadlines and client disappointment
"We scoped this task for three days to allow for potential issues – it only took two, so we also got a head start on the next item."
Figure: Good example – A realistic buffer results in a pleasant overdelivery and increased client trust
Tips to apply this rule
1. Estimate realistically
Avoid “sunshine estimates”. Add buffer time for the unknowns—because they will happen. Don’t just plan for the best-case; include the expected and worst-case as well.
2. Communicate clearly
If you’re ahead of schedule, tell the client. If you're falling behind, say so early. Clients are forgiving when you’re transparent—radio silence is what causes frustration. This will help minimize surprises at the Sprint Review. See our rule on having Corridor Conversations
3. Prioritize consistency over perfection
You don't have to wow every Sprint. What clients value more is predictability. Be the team they can count on.
“It’s not about hitting every target perfectly. It’s about reliably delivering over time.”
– Michael Smedley, SSW
Final thought
Software development is about more than code. It’s about building trust. And nothing builds trust faster than consistently delivering more than what you promised.
Video: The Secret to Client Trust (2 min)