Scrum and the Power of Primes

No not Optimus Prime, prime numbers! Someone posed the question as to why the “recommendation” of 7 members +/- 2 for a Scrum Team. Any Scrum larger than 7 members is out of the gate with a serious disadvantage, why you ask? Channels of communications… Agile and Scrum are all about the creation of high performance teams and since we have yet to evolve to the point where we can use telepathy, that means communications between team members is a critical success factor. So the question is, what does team size do to channels of communication?

Let’s say your team is made up of 4 individuals – As the Scrum Master you are managing 24 possible conversation streams (4x3x2x1=24). Grow your team by one (1) member to five and you are now managing 120 conversational streams – almost a fivefold increase. With a team of 7 members you have the staggering possibility to deal with 5,040 conversation streams.

Communication is what drives and defines the energy, spirit and cadence of your team. Open communication also drives collaboration and contribution cross functionally within the team, so if you want to spend your time getting sprints done as opposed to managing communication you will keep your team small.

In the early 2000’s there was a great illustration of Agile and Scrum at Oracle. 7 guys in Ireland imagined, coded and delivered a brilliant GUI based SQL explorer and admin tool that won critical industry acclaim and adoration from users. Pumped by the success of the product Oracle quickly grew the team to 59 individuals – version 1.1 of the product was a disaster, buggy, bloated and unintuitive.

The moral of the story is that successful high performance teams are small and light; if you can’t do it with a maximum of 7 members you’re either using the wrong technology or haven’t partitioned your scope properly. Heading past 7 members makes your project more likely to slip into a hybrid model.