So, how many team members should a scrum team have? The common rule of thumb is seven, plus or minus two. That is, from five to nine. Fewer team members and the team may not have enough variety of skills to do all of the work needed to complete user stories. More team members and the communication overhead starts to get excessive.
What is rational behind this number? What research has been done on the implication of having a scrum team of 10 or 15 or 20???
