I said in the previous post that one of the biggest problems brought about by a waterfall approach is the lack of feedback. The future users of the software get to see the software only when it is finished, when the opportunity to provide valuable corrections and suggestions are practically over.
Not only is it too late (or too expensive) to modify the program by then, the resulting software is sometimes not only bad, but even unusable.
Scrum directly addresses these problems by mandating that software must be developed iteratively, in iterations, and the at the end of each iteration, the software must be demonstrated to the stakeholders to get their feedback.
Scrum calls its iterations Sprints. Scrum recommends that Sprints be between 2 to 4 weeks. Whatever duration you choose, all the Sprint must be always the same duration. If you go for 2 weeks, then all the Sprints must each be 2 weeks.
This is in the ideal case of course. In practice a Scrum team that is just beginning to learn the ropes can choose a tentative duration to try out (say 2 weeks). If the team finds that 2 weeks is too short, they are free to adjust it (and all future Sprints). If they find that it suits them, they stick to it.
The key thing is to establish Sprints as a regular occurrence, like a heartbeat. Sprints of different lengths are like arrhythmia, with all the unpleasantness it brings.
The completion of each Sprint produces a finished subset of the product. The ideal is to deliver a working subset, preferably something that can be shipped. In practice this is not so easy to achieve, for some functions rely on other functions which may not fit in the current Sprint.
For example, an online store may include such functions as allowing the customer to search for products, order products, apply discounts, and have them shipped to an address of their choosing. Very often all of these functions cannot be built within a single Sprint. So which ones to build in order to product a shippable subset?
The Scrum team (together with the Product Owner) decides which functions to build in order to deliver working software. One such option could be to simply include only the search for products function. So at the end of the Sprint you end up with software that searches for products, and does nothing else. That is an acceptable choice.
It is far better than deciding to build all the user interfaces for all the above functions, but not have them work. If you do this, what you get at the end of the Sprint is not working software, rather, you end up with a glorified series of screenshots.
Back to feedback. At the end of each Sprint is a Demo of what was built. The Scrum teams demonstrates the current product so that the Product Owner (and other stakeholders) can review it and give their feedback. Is this what was envisioned? If it was, was it what you wanted? Very often, once we see the the incarnation of what we said we wanted, we come to the realisation that that is not really what we wanted.
The purpose of the Demo is absolutely NOT to show the Product Owner that the Scrum Team is working hard. No. The purpose is only feedback regarding the product. (There is a time when evaluation of the Scrum Team occurs, but this is not that time, and I will talk about it later).
If there is one thing that feedback causes, it is change. You can be sure that the feedback will result in changes, changes to what the software will do, and changes to what it is currently doing.
So what do we do with the changes? I’ll talk about that in the next post.
No comments:
Post a Comment