I love this approach to splitting up user story value by considering vertical slices through the technical solution.
Iterative and incremental development is a tricky art to master. Delivering very small increments of value takes some practice. With iterative development we must be happy to frequently revisit areas of the system that we are building as we learn more about them, which is quite different from the traditional approach (broad and shallow engineering versus narrow and deep).
This is where I believe the Agile Manifesto authors were coming from when they spoke about “Simplicity, the art of maximising the amount of work not done“. Implementing the simplest technical solution in order to deliver value quickly. It does not necessarily constitute the final solution, and it certainly does not mean “quick and dirty”. We still need code quality (unit/integration/acceptance tests), and the goal is to have a usable system. Something we ourselves would be happy to use and would be able to provide feedback on.
But for an individual user story we are simply trying to meet the goal of that story in the quickest and simplest way possible while providing an acceptable technical solution to meet that purpose. If the code is simple and maintainable we can easily build upon it if required, and the required architecture will evolve as we both iterate and increment.
So we want stories as small as possible (no more than a couple of days of work) and with the simplest acceptable solution under the covers. A good way of looking at it is “what’s the minimum amount of code I need to write to pass the acceptance tests?” (this approach of course leads naturally into the worlds of TDD and BDD, which I encourage you to read more about).
Working this way enables us to get early feedback on the feature and decide whether to invest more effort (via more stories) for that feature, thus allowing the flexibility for the product owner to prioritise a different area of the system if (s)he so wishes.
Some further reading about splitting user stories:
Have a great weekend everyone. Perhaps consider making the goal of your Sprint Planning meeting on Monday to split your stories down even smaller using some of the excellent techniques available. The benefits are numerous.