Slicing Features—vertically
Being interested in the topic of Feature Slicing you might already know the poster How To Slice A Feature and have read the Right-Sizing Features article on the SAFe website. But you’re still stuck and don’t know how to apply those rather general tips to your working environment? Then you should read on.
Why Feature Slicing
The goal of agile teams is to deliver the most value with as little effort as possible. This implies building products and software in short iterations in order to learn together with stakeholders on the outcome and to further improve them. Many teams are having trouble approaching the slicing of a Feature — especially if their environment is different from the classical functional UI development. That’s why we decided to start a pilot within the Data, Analytics & AI Group at Swisscom to develop a guide that is (for now) tailored for data-driven development. To do so, we have joined forces with our inspiring partner Creaholic to take a step forward into the way of slicing Features. In this article, we want to give you some insights on the first iterations we took.
Before starting, it is essential to differentiate between Features and Stories. The Right-Sizing Features article on the SAFe website mentions (amongst others) three points that differentiate Features and Stories:
- Features are visible «units» of business intent that the customer recognizes, and it’s at this level of detail that the customer can prioritize their needs.
- Features may span multiple user roles, stories and use cases.
- Multiple teams may work on the same feature, swarming together to deliver them quickly.
When it comes to the writing of Features we’ve already designed The Feature Writing Canvas. It helps you to write Features at a qualitatively high level and at the same time determine clearly who will profit from the implemented feature.
Know the need behind the request
Once the content of the Feature is clear and planning starts, questions about making the Feature smaller — so called Feature Slicing — arise. To be able to slice a Feature the right way it is crucial to understand the need behind your customer’s request. Only by finding this out you are able to define possible smaller portions of a Feature — be it in the way of a Minimum Viable Product (which is mainly to learn more about the ultimate product) or a Minimum Marketable Feature (MMF) which is about delivering value to the customer.
Let’s slice them vertically (end-to-end)
Some of the slicing techniques from Features may also apply to Stories and the other way round — and some Story Splitting techniques may apply as well for Features. But there are some patterns that you won’t find in Story Splitting which was one reason for developing The Feature Slicing Guide.
We did include the INVEST criteria in the guide as this is a powerful method to define Features. Talking to members of the Data, Analytics & AI Group at Swisscom we quickly found out that some «standard» slicing patterns which can be found in the How To Slice A Feature poster are already applied frequently. Specific challenges arise with requests like the buildup of new algorithms. It is really hard to build «half» of an algorithm and show it to a stakeholder. When building a data mart it should already be possible to build up more and more of its logic gradually. The goal of all mentioned slicing approaches in The Feature Slicing Guide is always to achieve a vertical slicing instead of a horizontal one.
In the case of a horizontal slicing, we started in a waterfall-driven approach to analyze everything. But after each phase (analyze, build, test) there was nothing to release or even to show to a stakeholder and they were not able to understand and give feedback. That’s why we wanted to switch to a vertical slicing approach where we focus on a small part of the solution and bringing them end-to-end in micro waterfall steps into production. Your stakeholders will now be able to make use of it and to provide valuable feedback.
The following image shows the behavior of horizontal and vertical slicing:
Now it’s time to bring in The Feature Slicing Guide which gives hints and asks questions to help reducing the size of a Feature.
The different approaches are focusing on:
- understanding the need to challenge the scope and solution
- reducing the scope, complexity and effort size
- building independent Features and design
- making use of different environments and tools
- limiting work in progress
Sometimes you must combine several hints, sometimes you will achieve the goal of smaller junks even by applying just one single approach.
Get the Feature Slicing Guide from Product Manager Tools
Sharing our insights on Feature Slicing, we hope that your slicing can improve as well. Let us know your feedback so that we can include it in future iterations of the Feature Slicing Guide.
