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How Many Scrum Teams Should You Be On? by Jordan Job

· scrum,team

This happens in companies that might already be doing scrum before they went to scrum.

They had a lot of scrum teams where one person can be assigned to three, four five projects at the same time. 😱

Usually, when I teach a class, I got questions like "I feel like I do have not any free time, is scrum supposed to be like this?" ⌛

"Is scrum supposed to be so meeting-heavy?".🪨

So let's eliminate a myth commonly associated with scrum, and explain by using math "How many scrum teams should you probably be on?".



Let's start doing the math:🧮

This is John!👨

John is a developer 🧑💻 that went through my scrum classes recently.

John is working for a company that is using scrum and they do 4 weeks sprint.

John works at a sustainable pace of 40 hours per week.🗓️

Over the course of the sprint, he works 160 hours per sprint.

John tells he had not a lot of free time. He said he has almost no free time.🤷

He spends most of his time in meetings and is just trying to remember what he is supposed to be doing.😵💫

John asks me: "What does Scrum have so many meetings?"

I asked John what meetings he has been attending, and he lists all the scrum events: sprint planning (8h), sprint review(4h), sprint retrospective(3h), and the daily scrums (15min * 5 days * 4 weeks = 5h).

John talked about the timebox for each event and added those hours up, the total of the time boxes in a 4 weeks sprint is 20 hours.

This is the maximum amount of time that should be spent in scrum events in a four weeks sprint.

Also, time boxes are scaled down proportionally for shorter sprints.

For example, scrum teams that use two weeks sprints usually timebox sprint planning in 4h.

Although, they could technically use the full 8h if they want to.

The maths we are about to do will apply to any scrum team regardless of how long their sprints are.

But back to the story🧚, after John added up hours of the scrum events, John said:

"Yeah! But that's only when someone is on one scrum team. No one in my company does that."

I begin to draw out how much time is spent in scrum events when someone is on multiple scrum teams.

I started with the number of teams, John's capacity to work at a sustainable pace, the total hours spent in scrum events, and the number left after attending the scrum events.

Let's see if John can be only in one scrum team, how much time does it leave him to work?

John has 160 hours during the four weeks sprint, and 20 of those hours would be spent in scrum events (shorter sprints would scale down these 20 h), so John has 140 hours of working time after attending scrum events.

What if John was in two scrum teams? 120h left

What if John was in 3 scrum teams? 100h left

What if John was in 4 scrum teams? 80h left

What if John was in 5 scrum teams? 60h left

John has eyes got wild and a smirk 😏 came across his face as I drew this on a whiteboard.

He began to realize why he had very little free time.💡

John was on three scrum teams.😱

Also, I haven't talked about Product Backlog Refinement (PBR).

Refinements usually consume no more than 10% of the capacity of the development team.

Let's just use 10% to make this math easy.

10% of 160 hours is 16h.

So let's apply that to John being in more than one scrum team.

How much time does John has left after doing scrum events and PBR?

With John being on three scrum teams, he has not a lot of time left: 52h.😱

But I have met people who have been in 5 scrum teams. According to simple math (-20h), they probably not working at a sustainable pace or they are not able to participate as a full team member.

Having one person be a member of three, four, or five scrum teams is probably too many; even being in two scrum teams dramatically lowers the amount of working time someone has during his sprint.🚨

☝️ If you want to strive for productivity and allow people to focus, scrum team members should probably be only on one team.

I mentioned that John is a developer, so this math obviously applies to development team members.

What about Product Owners(PO) and Scrum Masters(SM)?

PO and SM do not have to attend daily scrums.

So they cut out some time in scrum events.⏳

And on a side note, if you thought PO and SM would be required to attend the daily scrums, you should probably brush up on the scrum guide.

But even if the PO or the SM do not have to attend the daily scrums, they often do as the scrum team can find it beneficial.

Another thing to consider is scale scrum.🪜

When scaling scrum, there should be one PO per Product backlog, and there should be multiple scrum teams working on that product.

Depending on how scrum is scaled, and how many scrum teams are working on one product, a PO could serve as the PO of many scrum teams.

SM though is not quite as lucky.

SM has three 3️⃣ primary areas of service: to the development team, to the PO, and to the organization.

In a scaled environment, scrum teams may assure many impediments across those layers of service.

So SM could achieve economy of scale by being on multiple scrum teams but by doing so they limit their opportunity to actually spend time with their team.

And if they do spend time with their team, they're losing time that could be spent resolving any impediments.