I would like to start with describing what cycle user story goes through before it becomes READY for sprint planning meeting and how PO handles this cycle.
For sure there are many best practices to get stories READY and write proper stories. Instead of focusing on story-writing itself, here I will cover PO workflow to them ready.
So, here are my 5 cents…
Assumption: user stories are part of shaped big wish (called epic), that is part of Agile release/roadmap and takes place on “storymap” that had been presented to development team some time ago.
What does this means?
This would mean that:
- Value brought by an epic (and future user stories) is clear to everyone;
- Possible big “underwater” problems it may cause surfaced (reworks, performance, missing data, uncertainty, etc.);
- High level estimates are given to an epic;
- Big questions are addressed;
As next step PO prepares epic further, splits into particular stories, sizes each of them and “hones” acceptance criteria (aka satisfaction criteria). To proceed we need to know what does INVEST mean.
What is INVEST?
Things PO should keep in mind when doing story-writing and story-splitting is “INVEST” rule. It stands for:
- Immediately Actionable – so that team can start working on it immediately;
- Negotiable – so that can be quickly made smaller/bigger by removing/adding scope of acceptance criteria (AC);
- Valuable – so that everyone understands what value it brings to an end user;
- Estimable – so that it can be estimated with user story points or ideal hours;
- Sized to Fit In – so that estimates fit in established iteration length;
- Testable – so that has understandable and achievable acceptance criteria;
Splitting an epic
Then it comes to the split itself. I suggest doing the following way:
1. Have a pencil and paper talk with your PO peer(s) on the epic before splitting:
- define overall description (As a WHO I want WHAT so that WHY);
- agree on the way to reach WHAT (draft acceptance criteria, aka AC);
- write AC down. You will end up having many AC, e.g. 30 or more;
2. Request, get and provide stories with everything that makes them immediately actionable (e.g. designs, data, clarifications, everything that has to do with 3rd parties, etc.);
3. Define story split logic, so that they all can be worked on quite independently and placed in a sequence that satisfy following criteria:
- upper stories do not require functionality of lower stories (and lower stories do not impede implementation of upper stories);
- functionality is split logically, trying to keep stories ~same size (remember, best sizing of stories is 3-8 user story points);
- upper stories allow user to see maximum valued functionality first;
4. Define each story description and split overall AC accordingly. Keep in mind that at this point new stories will pop up (I call them “conjunction stories”). The rule is easy to understand.
Epic Box Principle: “As soon as you start emptying virtual box of epic functionality, removing and shaping story after story out of it, you will find out something that is still there and was not your initial plan”.
If your plan was to split epic into 4-5 stories, you may end up with 7-8 or so. That is one of the reasons that explains why usually epic level estimates are smaller than sum of estimates of all corresponding stories.
Important hint: do not hesitate to split as combining is way easier. Splitting is good exercise because enforces to think through value->solution again and discovers potentially hidden problems, functionality etc. Another effect of splitting bigger stories into smaller is reducing doubt (and therefore risks) team will have associated with big story. It turns afterwards into saving user-story-points…
Therefore, it’s way better to have detailed backlog rather then let team estimate their doubt wasting story points on your inability to think through solution and side functionality that may popup during implementation of bigger chunks.
Remember: as PO you are in charge of what team does next and need to have stories prepared accordingly.
5. Peer review all stories with your colleagues after you consider them as READY to see what is missing, question how each AC may be interpreted, best guess on possible estimation;
6. Re-do steps 2-5 until stories are INVEST and READY for sprint planning meeting (SPM);
To be continued … (“Getting them through sprint planning….”)