Group Size

Team composition: Group size

1. Does the process of adding manpower to project team hasten the process of completion of projects? Why?

It takes four people to play a string quartet, two crew members to fly a Boeing 737 aircraft, and twelve persons to form a full-sized jury. Not a person more nor a person less will do, so those who compose such groups can focus on matters other than the size of the performing unit. More commonly, however, managers who create work teams in organizations have considerable discretion about team size. Although manages sometimes form teams that are too small to accomplish their work well, the far more common and dangerous mistake is overstaffing them.

Fredrick Brooks was the manager of the systems programming effort at IBM that in the 1960s created OS/360, then the largest such effort ever undertaken. As almost always happens with large-scale projects that involve a great deal of coordination and uncertainty, the project tended to fall behind schedule. The temptation in such cases is to compute how far behind the project is and then add staff to make up time. So if the project is a dozen person-months behind, perhaps a dozen people could be assigned to it for one month to get back on schedule. That has no better chance of working in software development, Brooks says, than would a scheme to produce a baby quickly by assigning nine women to be pregnant for one month each. In fact, adding people has the opposite effect, which led to the formulation of Brooke’s Law: “Adding manpower to a late software project makes it later.”

2. Do groups/teams work always at their potential productivity? Why?

Psychologist Ivan Steiner reached the same conclusion in his analysis of the effect of group size on group productivity. The potential productivity of a group (that is, what the group theoretically could produce if member resources were used optimally) increases as size increases – but at a decreasing rate. Each new person adds something,...