As you consider hiring plans for next year, one aspect of your organization that you should give some thought to is what is the optimal team size?  You may have heard of Amazon’s rule of “two pizzas”, which basically says a team should be no larger than what it takes to feed with two large pizzas.  If our experience in feeding engineers pizza is typical, this means about 8 to 10 people.  As a general rule, we think this is fine but we have some other factors that we recommend incorporating if you want a more precise number.  These factors include experience of the managers, how long the team has been together, and manager responsibilities.

Before we explore the factors that influence optimal team size, first we should discuss why team size is important.  Consider a team of two people, they know each other’s quirks, they always know what each other are working on, and they never forget to communicate with each other, sounds perfect right?  Well consider they also don’t have enough engineering effort to tackle big projects in a timely manner, they don’t have the flexibility to transfer to another team because each one probably knows stuff that no one else does and they probably have their own coding standards that are not common among other two person teams.  Obviously, small teams and large teams each have their pros and cons.  They key is to balance each to get the optimal result for your organization. 

The first factor that you should consider is the experience level of the managers.  If the managers are experienced they should be capable of handling more direct reports.  New managers should be given fewer direct reports in order for them to have time to develop their management skills.  Keeping resource maps up to date for 15 engineers can be overwhelming for a new manager but one that has done it for years would have no problem doing it.  If you are filling vacancies in your management ranks try to be as detailed in the organization chart as possible spelling out the manager positions that you are keeping for junior managers and those that your are expecting to hire a more senior manager.  If you have a team that will be assigned a very large project and therefore needs to be large in numbers, mark it down as requiring a more seasoned manager.

The next factor to consider is how long the team has been together.  A team of twelve people who have been together for eighteen months is likely to have entrenched processes that make management of them easier.  The team may already have mentoring relationships established or clear divisions of code for easier feature assignment.  A brand new team probably has none of these as well as no bonding and possibly personality conflicts that need to be worked through. 

The last factor that we consider key to determining the optimal team size is what management responsibilities are expected from the manager.  Do you expect managers to conduct a weekly half hour one-on-one meeting with every engineer?  Do your managers need to create and maintain resource maps for the engineers?  Do managers need to periodically assign themselves features to code?  All of these questions and more will influence how many direct reports they should have.  Obviously the more managerial or development tasks that you expect your managers to handle the fewer team members they should have.  If you have a Project Management Organization that helps managers handle assignments and statuses, the teams can be much larger. 

So the answer to how large the team should be is, it depends.  It depends on a variety of factors that we’ve outlined here.  As you start preparing your budget for next year, take a few minutes to consider these factors and ask your existing managers for feedback on how their team size has affected their ability to perform as a manager.