Scrum Team Size: Easy Steps to Create Ideal Team

Picking the right Scrum Team size and composition can be quite confusing when you first begin. Which makes many teams struggle with defining the perfect structure and knowing how to go about rearranging and modifying their current structure. To help you out in this quest, let’s explore the topic and discuss the industry’s best practices.

If you are not yet familiar with the Scrum Team composition, check out this post:

3 Scrum Team Roles and Responsibilities

What is a Scrum Team?

As described in the Scrum guide, a Scrum Team is a cohesive unit of professionals focused on one objective at a time, the Product Goal. The Scrum Team is composed of 3 Scrum roles – the Developers, a Product Owner, and a Scrum Master. All of these contribute different responsibilities that help deliver valuable Increments.

This small team of people is a fundamental part of Scrum. And as such, it is an important aspect of successful Scrum implementation.

The Recommended Size for a Scrum Team

According to the Scrum guide, any Scrum Team should be made up of 10 or fewer people. So, in a small project, you would have a Scrum team of around 5 people – 3 Developers, 1 Product Owner, and 1 Scrum Master. And in a large project, your team would consist of 9 people – 7 Developers, 1 Product Owner, and 1 Scrum Master.

If a Scrum team size is bigger than 10 people, it should be split into two connected teams. These two teams would then share the same Product Owner, Product Goal, and Product Backlog, but would run their Sprints individually. You may find that there are effective Scrum Teams that exceed this guideline of no more than 10 people per team. And while this may work for them, it is really not recommended to start with a large team as you begin the Scrum journey.

In fact, the smaller the Scrum Team, the easier it will be to manage. There is less communication, collaboration, and a clearer distribution of responsibilities. So, my advice would be, to start small and then expand if needed.

The Minimum Team Size for Scrum

Now that we are talking about the smaller Scrum Team size, let’s see how should you determine what is the minimum number of people for your team.

Most Scrum practitioners agree that the minimum Scrum Team size should be at least 4 people. In this scenario, we would have 2 Developers, 1 Product Owner, and 1 Scrum Master. A team that is smaller than this would become too unbalanced or would require the team members to take on more than 1 role at a time. Which is possible, but not ideal, especially when you are just starting out.

However, instead of focusing on a specific number, you should also think about the needs of the team. This way, you will be able to determine a minimum Scrum Team size that delivers the best results. Here is what you should consider:

Does the Scrum team have required skills to build the Product. Make sure the team is trully cross-functional and can perform without outside help.
Is the Scrum Team able to self-organize? Are the team members able to manage their own workload, or should they be eased into it?
Is the Scrum Team hierarchy flat? All the team members should be equals and there should be no sub-teams within a Scrum Team.
Are the team members dedicated to a single team? It is best, when the team members are focused on the goals of a single team.

By answering these questions, you will be able to define the minimum Scrum Team size that answers the needs of your project and goals.

When Should a Second Team be Added?

Now that we discussed the minimum Scrum Team size, let’s talk about the other side of the spectrum. The maximum Scrum team size and when you should consider splitting your team into two.

As mentioned above, according to the Scrum guide any Scrum Team larger than 10 people, should be split into 2 teams or reduced in size. This recommendation comes from the simple fact that having more people on any team creates additional relationships between them. And for a team to perform well, all of these relationships must be strong. Now the issue is, that as we add on people, the number of relationships increases exponentially. Here is a simple chart to reflect this effect:

Team size	Relationships
5	10
7	21
9	39
11	55

This is a visualization of the same effect for a better understanding:

So, as your team grows, maintaining these strong relationships becomes harder. In most cases, the team members have to start choosing whether they spend more time on building those relationships or withdraw and concentrate on work. In either case, either the productivity or the effectiveness of the team suffers.

So, should you immediately reduce your team as you exceed the 10 team member mark? No. But you should be conscious of the strain that having more people on the team has and make the transition into two connected teams when it is appropriate for your process.

Signs that the team is getting too big

Another thing that will help you decide on when it is time for the split is watching out for these signs in your Scrum events:

Going over the 15-minute mark during the Daily Scrum. If your team members are effective and coincise during this meeting, but you keep running over the maximum time-box for this event, it may be because your team is too large. The team members will most likely become disengaged and won’t be able to follow the progress of other team members whne this meeting extends.
Inneficient Sprint Planning. When a team grows, it can become harder to agree on the item delivery time and size. While this is normal to some extent, if you are having constant issues and innefective planning sessions it may also be a sign that it is time to split up the team.
Struggling to find common ground during Retrospectives. Again, finding common ground with your team is always a little challenging as there are different preferences at play. However, if you start to see the growing number of dissagreements, it is a sign of weakening relationships within your team.

While the above signs are not 100% proof that the team should be split up, they are good indications of trouble within the Scrum Team. And as such, they could indicate that splitting the team would benefit all parties. However, the final decision still remains with you.

How to Split the Scrum Team?

If you have decided it is time to split the team, there may be questions on how to approach it in the best way.

First, and foremost, make sure both of the newly formed teams meet the minimum Scrum Team size requirements laid out above. They must have all the competencies required to deliver a product increment, be self-organizing, and respect the flat structure as well as each other.

Besides these initial factors, think about which team members perform well together and take account of the already existing relationships. If it makes sense skills-wise, try and put such people together. Thus allowing them to continue working within the current strong relationships instead of having to build new ones.