You’re at sprint zero. You’ve got a new team. You’re new to scrum. You’ve never quite managed to stick to the Scrum framework. All reasons why you might not have a velocity. I’m sure there are more, but these are the most common. What do you do? How do you know how much you’re going to be able to fit into a sprint?
Yes, I’m serious. If you’ve groomed your product backlog for the first sprint, estimated your stories and refined those estimates and broken down larger stories, then the only thing left to do is guess. Gather your team around and ask them “What do you think you can fit into this sprint?”. Once the team has picked from the highest priority stories and agreed that they think they can fit the work in, ask for their commitment. It’s at this point that you’ll need to help the team decide whether or not they’ve over committed. Most teams almost always start out thinking they can deliver more than they really have the capacity for. It’s not because they’re showing off, or because of any kind of arrogance, they actually do think they can deliver what they’ve said they will. Remind them that, while the stories are well written and the acceptance criteria well defined, they are just the start of a conversation with the business and things could change.
Your team will probably decide to knock of one or two stories and right now, that’s fine as they can always go back into the sprint if you find yourself running out of stories half way through. Once there’s a commitment, add up the story points. That’s your predicted velocity. It may not be accurate and it’s quite probably wrong, but right now, right this very minute it’s the most accurate idea you have of how much you can deliver in your sprint.
Why is this useful? Well, it will give your team a target, they’ll want to actually hit that velocity prediction as they’ve said they would. It’ll also come in useful for release planning and having some kind of vague idea of when your product might be delivered. You know least about how long or how complex a task is right before you start it, but now you’ve got some benchmark. You can add up the rest of the story points on your backlog, divide by the predicted velocity and have a figure which is roughly how many sprints you’ll need before you have delivered your product.
That is something that the product owner will shit himself with excitement about. Assuming he hasn’t asked you to translate that into a gantt chart.