Can I start a new sprint without delivering the last one?

Question

I'll try to simplify my questions and avoid story telling.

1) Can I start a new Sprint without delivering the last one?

2) During Sprint 2, can I include items into Sprint 1?

3) How many undeliverable Sprints can I have in my product?

I am facing a flexibility problem where the client says that he can change the framework any time and in any way he wants. He argues that Scrum predicts flexibility.

I'd like to know if there is a 'Scrum way' to deal with this, 'cause in the Scrum Guide I didn't find anything.

Answer 1

1) Can I start a new Sprint without delivering the last one?

It depends on what you mean by "deliver". If you are following Scrum, each Sprint results in a potentially shippable or releasable increment. That doesn't mean that each Sprint has to be shipped, released, or delivered to a customer.

2) During Sprint 2, can I include items from Sprint 1?

If you have unfinished work, then yes. The textbook answer is that, at the end of a Sprint, any Product Backlog Items selected for the Sprint are returned to the Product Backlog and the Product Owner can choose to reorder them appropriately. However, unless the priority has shifted, the result is often that they would "roll over" from one Sprint to the next.

3) How many undeliverable Sprints can I have in my product?

Zero undeliverable Sprints. The end result of every Sprint is supposed to be potentially shippable or releasable. However, you may have undelivered Sprints. That's a key distinction.

I am facing a flexibility problem where the client says that he can change the framework any time and in any way he wants. He argues that Scrum predicts flexibility.

I'd like to know if there is a 'Scrum way' to deal with this, 'cause in the Scrum Guide I didn't find anything.

Scrum is a framework. It doesn't answer every question or address every situation that you may encounter. But it does often provide guidance. If there's nothing in the Scrum Guide, you can always fall back to the Manifesto for Agile Software Development and its 12 principles.

If you do break one of the rules in the Scrum framework, you are no longer doing Scrum. This isn't a bad thing. There are plenty of good ways of working that aren't Scrum, yet are still consistent with the values and principles of Agile Software Development and/or Lean Software Development and will result in successful projects and working relationships with stakeholders.

Answer 2

First I'll answer your actual questions:

Can I start a new sprint without delivering the last one?

Yes.

During Sprint 2, can I include items into Sprint 1?

No. A Sprint is a timebox. It has a start-date, an end-date, and a Sprint Goal. Once the end-date has passed, the Sprint is done. Without a time machine, it's impossible to add more work into it at that point.

How many undeliverable Sprints can I have in my product?

Hypothetically infinite.

Please note that, from the Scrum Guide (emphasis mine):

The heart of Scrum is a Sprint, a time-box of one month or less during which a "Done", useable, and potentially releasable product Increment is created.

At the end of every Sprint, your product should be in a state where you could release, if you need to. That doesn't mean that you have to release at any given time.

how can possible many increment exists at same time?[sic]

They can't. Each increment is a Sprint, and each Sprint is a timebox, not a collection of work. You can't have two Sprints co-existing, because Sprint n must end before Sprint n+1 begins. Jan 5 cannot happen at the same time as Jan 6.

Also:

I am facing a flexibility problem where the client says that he can change the framework any time and in any way he wants. He argues that Scrum predicts flexibility.

This seems to have nothing to do with an unreleased Sprint. Please either clarify or ask a separate Question.