Planning in Scrum: story points and planning poker (2/2)

This is the second article about Planning in Scrum

Scrum

What does Scrum teaches us about planning? To be precise, nothing. The only thing Scrum demands is that you plan. There is a timebox in Scrum that dictates that you plan, the timebox is about 5% of the sprints hours. So for a sprint of a month, you should take a day to plan, for a sprint of a week you should take two hours. 

In this timebox, there are three activities. At first the value of the sprint is determined. What value will be added this sprint, what will be our sprint goal? Then the work that needs to be done to achieve that  goal is gathered. The last activity is to determine how the work is done. 

To be honest, I rarely experience teams that do all three. But one of the most important things here is that in Scrum it is mandatory that you plan.

Story Points

So what about those Story Points (SP) then? Hate to tell you, Story Points are not a part of the Scrum framework. But, what are they? Story Points are numbers we give to work items to indicate complexity. Complexity is more then just time, it is also about how difficult it is to achieve the outcome. A small simple task may be one SP and a large complex one 100 SP. What about a small complex one? And a large simple one? Those are somewhere in between.

Story Points can be compared to travel distance. If you travel from Paris to Berlin by car you need to drive about 1058 km. This distance won't change, it will always be around 1000 km. We can say the distance between Paris and Berlin is 1000 SP. And how long will we need to drive by car to get from Paris to Berlin? It depends. If we don't take a break and drive a steady 100 kph we will reach our destination in about 10 hours. We will not account for traffics jams, fog, detours etc. In this case 1000 SP will take us 10 hours to complete. But if we put in the variance of the troubles on route it is safe to say that we will reach our destination in 11 hours plus or minus an hour. In this case 1000 SP is comparable to 10-12 hours. 

Therefor we can use SP in planning to talk about effort of work, but we won't be sure when the work completes.

Empirical

Planning in Scrum with Story Points is an empirical process. We need to learn that we, as a team, understand the size of SPs. Before we start planning we can build a reference board with work items we consider one SP and work items that are of another order. We can use this board for all future planning. The more we plan, the better we get at planning, the better we will understand what it means to have a work item of one SP and a work item of 30 SP. 

The better we get in planning, the better we get in becoming predictable. Stakeholders love it when we are predictable and they hate it to be surprised (but when you surprise them, better make sure it's a good surprise). Predictability can be measured in estimated SP / achieved SP * 100%. The closer to the 100% the more predictable a team is, the better they understand the work that needs to be done, and the better their performance.

Planning Poker

We can also use the reference board to derive a game of: Planning Poker. With Planning Poker we keep the reference stories in our head (or we take a glimpse on the board) and we guestimate how many SP a story is. Planning Poker is not a part of the Scrum framework, it is just used a lot to facilitate planning. The cards are most of the time based on a numbered sequence based on the Fibonacci sequence. This sequence starts with a zero and a one and the next number is the sum of the last two: 0 1 1 2 3 5 8 etc. Some card sets use the exact numbers, some a simplified set.

In most Planning Poker sets there is a 0, a coffee and a question mark. Get rid of those. There is no work that is worth 0 SP; it would mean the work is already done and shouldn't even be considered to be taken up in a Sprint. The coffee is for indication of a break; still communication in a group can be done with our mouths and it works much better. The same goes for the questions mark; if you have a question, just ask.

With Planning Poker cards are played in two rounds and team members guess how many SP a work item is. Science has proven that the bigger the group, the better the estimate. Therefor everybody needs to estimate, even if they think they don't know how to solve the story. Anyone who abstains won't learn to improve in planning or ask the right questions.

Planning Poker is not about poker, it is about planning and understanding what needs to be done to achieve the Sprint goal. It cannot be played wrong, as long as there is feedback making sure we can learn from each other.

Conclusion

Planning is an empirical process and hard to master. Planning is easier with references. Planning in Scrum is mandatory, figure out the best way how to do it with your team. And if you decide to work with Story Points and planning poker, take the time to understand what you are doing.