When looking at improving performance the first thought is often to increase the size of our development team; however, a larger group is not necessarily the only or the best solution. In this piece, I suggest several reasons to keep teams small and why to stop them from getting too tiny. I also look at several types of risk to consider when looking at team size: how team size effects communication, and the possibility of individual risk and systematic risk.

Optimal Team Size for Performance

The question of optimal team size is a perpetual debate in software organizations. To adjust, grow and develop different products we must rely on various sizes and makeups of teams.

We often assume that fewer people get less done, which results in the decision of adding people to our teams so that we can get more done. Unfortunately, this solution often has unintended consequences and unforeseen risks.

When deciding how big of a team to use, we must take into consideration several different aspects and challenges of team size. The most obvious and yet most often overlooked is communication.

Risk #1: Communication Costs Follow Geometric Growth

The main reason against big teams is communication. Adding team members results in a geometric growth of communication patterns and problems. This increase in communication pathways is easiest illustrated by a visual representation of team members and communication paths. 

Geometric Growth of Communication Paths

Bigger teams increase the likelihood that we will have a communication breakdown.

From the standpoint of improving communication, one solution that we commonly see is the creation of microservices to reduce complexity and decrease the need for constant communication between teams. Unfortunately, the use of microservices and distributed teams is not a “one size fits all” solution, as I discuss in my blog post on Navigating Babylon.

Ultimately, when it comes to improving performance, keep in mind that bigger is not necessarily better. 

Risk #2: Individual Risk & Fragility

Now a larger team seems like it would be less fragile because after all, a bigger team should be able to handle one member winning the lottery and walking out the door pretty well. This assumption is partially correct, but lottery tickets are usually individual risks (unless people pool tickets, something I have seen in a few companies).

When deciding how small to keep your team, make sure that you build in consideration for individual risk and be prepared to handle the loss of a team member.

Ideally, we want to have the smallest team as is possible while limiting our exposure to any risk tied to an individual. Unfortunately, fewer people tend to be able to get less work done than more people (leaving skill out of it for now).

Risk #3: Systematic Risk & Fragility

Systematic risk relates to events that will affect multiple people in the team. Fragility is the concept of how well structure or system can handle hardship (or changes in general). Systemic risks are aspects shared across the organization, this can be leadership, shared space, or shared resources.

Let’s look at some examples:

  • Someone brings the flu to a team meeting.
  • A manager/project manager/architect has surprise medical leave.
  • An affair between two coworkers turns sour.

All of these events can grind progress to a halt for a week (or much more). Events that impact morale can be incredibly damaging as lousy morale can be quite infectious.

In the Netherlands, we have the concept of a Baaldag (roughly translated as an irritable day) where team members limit their exposure to others when they know they won’t interact well. In the US with the stringent sick/holiday limits, this is rare.

Solutions to Mitigate Risk 

Now there are productive ways to minimize risk and improve communication. One way to do this is by carefully looking at your structure and goals and building an appropriate team size while taking additional actions to mitigate risk. Another effective technique for risk mitigation is through training. You shouldn’t be surprised, however, that my preferred method to minimize risk is by developing frameworks and using tests that are readable by anyone on your team.