One of the ways Scrum helps unite team members is through a mandate that teams remain small. Most Scrum literature recommends that teams be made up of seven cross-functional members (give or take two). Certainly, limiting the number of “communication channels” allows teams to engage in high-impact collaboration without too much of a margin to leave anyone in the dark. In fact, there’s a relatively straightforward equation to illustrate how, as team members are added and channels of communication increase, maintaining communication with the entire team becomes a considerable challenge.
The formula, in which “S” equals the number of communication channels and N stands for the number of team members, can be represented as: S=(N(N-1))/2
Interestingly, as team members are added, the value of “S” (i.e. the number of communication channels) rises dramatically. That is, if a team of six added two more developers to its team, the size of the group would increase to eight, but the total number of communication channels would balloon from 15 to 28. Suddenly the effort associated with communicating to every other team member has nearly doubled.
Although Scrum teams are recommended to be small, the framework guards against “group think,” i.e. a passive herd mentality, by asking that teams be composed cross-functionally. In other words, Scrum teams should be created to represent a range of job functions without much overlap. Where traditional, sequential development-better known as ‘waterfall’-grouped teams by function (testing, QA, etc.), Scrum prefers that all “phases” of development be present in the single cross-functional team. As such, a single Scrum team would likely include a mix of software engineers, architects, programmers, analysts, QA experts, testers, UI designers, and so on. When individuals with different skill sets, areas of expertise, and development experience come together for the kind of collaboration that Scrum enables, it ensures that multiple perspectives are considered. In fact, when individuals with such diverse backgrounds brainstorm on a problem, they may hit on a new solution as a group that they couldn’t have reached independently.
On the flip side, imagine a team of 20 trying to work together to resolve a particularly difficult problem. Because of the sheer number of people, a leader-or a handful of them-would likely emerge and, as a result, some team members might passively follow along. Or something worse might happen: The size of the group might keep it from making a fully considered decision-or any decision at all.