Tuesday, November 25, 2008

Flexible scope - A magic bullet?

Everyone agrees that you can’t both have a rigid deadline and a rigid scope. We’ve been there, Done that, Got the g***amn t-shirt. Software Development is not mass production and last time I checked I wasn’t able to foretell the future. We want to avoid projects where both the scope and the date are fixed. That’s one of the first lessons every developer learns… And that is one of the key things that Scrum brings: you develop in iterations, you timebox and you ensure you have something to deliver all the time, especially release day. Yay!

Timeboxing means the date should be regarded as fixed. Wow, there’s an easy sell to upper management…! But as a consequence we
have to allow the scope to flex… Simple enough? Well, allowing the scope to flex might not be as easy as it seems. “Flexible scope” as a concept is easy enough to understand, but it’s not something that happens by itself just because you say “we do Scrum”, develop in iterations with beautiful sprint planning sessions and sprint reviews.

I’ll illustrate with a scenario that I’ve seen in reality several times:

Let’s say you’ve started using Scrum, and one of the key selling points to upper management was: “In Scrum we never move the deadline, we promise to try to always have something releasable at the deadline. I can’t promise exactly what, but we won’t ever need to move the date”. Good start!

So, now you start working. The team is working on a release of (let’s say) two major features (each consisting of several smaller “parts”). The Scrum Product Owner and others work on breaking down the scope(s) into User Stories. But they’re not really familiar with Scrum and the stories they produce are poorly formulated, and are done without them really understanding what a User Story is and what to think of.

Still, eventually a product backlog is ready. But, again since the Scrum Product Owner might not be that familiar with Scrum there is not much effort or thought put into the prioritizations of the stories in the backlog. Anyway, the team starts their sprint with a sprint planning meeting and grabs whatever is on top of the backlog.

Once rolling, the team execute the sprint with little or no regard to the priorities. Everyone grabs a story each and start working.

Work continues along those same lines sprint after sprint. And stuff actually do get done. Progress is OK, people feel OK. So far so good?

Now, when you approach the intended release date, you look closer into what’s been done so far and you conclude that there are still several critical things that aren’t ready yet, or that maybe haven’t even been started yet. In addition, you conclude that there are critical tasks remaining for each of those stories which you previously thought were “Done” – tasks such as integration testing, string translation, code reviewing or similar. Ouch.

At this point, what are your options?
  1. The "easy" way out is to postpone the release date, i.e. effectively breaking the timebox rule. …Scrum breaking down. Oh misery…! And you had such an easy sell to upper management with the fixed-date thing... And all you do is move the date and then have the same problems once more, but that time you've sortof used up your goodwill and no longer have the luxury (?) of being able to postpone the date...
  2. Crunch! There's that word again... But you think "Just this time… This release was special...". You make up excuses about why you’re where you are, and call for overtime. Have people come in a little earlier and stay a little later. Have them come in those last few weekends. Not to mention those last days before deadline. So, the team works overtime, they put in extra hours, and not surprisingly quality suffers, people suffer, shortcuts are taken everywhere… Anyone recognize this?
  3. Flex the scope by lifting out the entire feature from the release. Since there are still critical stuff remaining you don’t have the option to just abandon parts. All you can do is lift out the whole feature. That doesn’t give such a good impression of the whole “flexible scope” mechanism, now does it? “Yeah well, in Scrum we don’t move the date, so we have to let the scope change, and that means removing a feature from the release. We have to allow that. That’s Scrum.”. A job well done. No, this is not what “flexible scope” means.
Those are really the only three options. And what’s even worse is that this is probably not discovered until very late. With only days or a few weeks (best case?) remaining until the scheduled release date… This is Scrum failing big-time!

So, the point I want to make here is that we need to be very careful so that we really maximize scope flexibility. The main mechanisms in Scrum which are affecting this are:
  1. Strict prioritization
  2. Ability of adhering to Definition of Done == Releasable.
  3. Skillfulness of breaking down a scope into user stories
To me “strict” means that we both prioritize AND stick to it, by actually working on things in priority order. If we don’t have a prioritization we can’t really say that we have done all in our power to have everything “critical” or “most important” (or whatever value you want to put in the prio) ready by the time the timebox ends. If you’re not careful, the “completed” part of the scope may be any combination of important and less important things, and (what’s worse) the same is true for the stuff that isn’t done yet.

Prioritizing the backlog needs to be intelligently done, and only 1 person should be allowed to have the final decision about a story’s priority: the Scrum Product Owner. I recommend thinking of the importance in terms of “Business Value”. But be careful; it doesn’t only mean value as in dollars and cents (or Swedish Krona and Öre ;-)). The keyword here is Business. Think of it in terms as Value to your Business, including your own internal business of developing stuff. So things that for example are “
architecturally significant” (I’ll post an article separately about this topic, some day) might get a high Business Value because it is important for the architecture and the consecutive development of other stories - even though the story itself may have less of an obvious value to the end user, the customer, your accounting department or your shareholders (but remember: if it is architecturally significant it is most likely valueable to the customer and end user too, it's probably just a matter of thinking about it hard enough and being able of formulating it in words).

The Definition of Done applies to how you “complete” stories. I’ve posted entries here in the past about this and I won’t go into details here. I just want to point out that adhering to the Definition of Done affects your ability of flexing the scope, because you ensure that you stay in control over what’s remaining; you stay on top. The things that have been done are really “done” and are really releasable, there are no hidden piles of work under the rug. I hate surprises and Definition of Done is my best friend :-).

A largely contributing factor both to your ability of adhering to the Definition of Done, and to your ability of following a prioritization, is how good you are at breaking the scope down into User Stories. Don’t regard the scope as a big monolithic lump of functions (e.g. the waterfallish term “Requirements”). Instead, you need the stories to be independent, finishable, valuable and estimatable. A good guide on the way of thinking you want to have is the I.N.V.E.S.T. acronym (stories should be Independent, Negotiable, Valuable, Estimatable, Small and Testable). Writing stories is a skill that you have to work actively with and continuously try and improve.
Don’t be alarmed though; it’s not rocket science. Some breakdown is better than none, and you shouldn’t make such a big deal out of it. Learn by doing. Try different approaches to formulating stories, try the INVEST acronym, try other ways. As long as you understand that the “quality of the breakdown” will affect a lot.

So, to wrap things up: with intelligent scope breakdowns, by following the prioritization and the Definition of Done, we can be more than reasonably sure that the e.g. 85% of the scope which is “ready” when the timebox ends, is really ready, and the remaining 15% is not half-started and we don’t have dependencies between the ready 85% and the remaining 15%. We know we can release
something – and that something is actually something valuable (hopefully even the maximum value).

There. Long post this time. But I like this subject. And it's an important one. I’d be glad to learn about other peoples’ experiences. Cheers! My food is getting cold.... ;-)

3 comments:

  1. A good article! I have been working in Scrum for over two years. Not a strict Scrum, but we tried to follow the best practices and improve our understanding. I am now writing a comparison of Scope Management in PMBoK and Scrum and find this article very helpful. Do you have any other comments on Scope Management in Scrum? I would love to read them.

    ReplyDelete
  2. Thank you for your comment!

    I do have lots of opinions about this, but I'm not sure I have any other articles that are spot-on what you're writing about. But I picked a couple of labes and articles from my archive that you can read if you like, that are somewhat related. There are more, I think, but these are some:

    http://scrumftw.blogspot.com/search/label/Achieving%20a%20flexible%20scope

    http://scrumftw.blogspot.com/search/label/Change%20Management

    http://scrumftw.blogspot.com/search/label/Refactoring

    http://scrumftw.blogspot.com/2008/12/done-or-complete-how-to-develop-in.html

    http://scrumftw.blogspot.com/search/label/Agile%20specification

    ReplyDelete