No More Hierarchy, but Heterarchy.

A recent study ("The Riddle of Heterarchy") indicates that the traditional "Assigned leadership" is not working well especially in a creative team, but "Emergent and collective Leadership" is outperforming. 

1. Teams are likely to operate better when there are a number of members with leadership potential (fears of rivalry notwithstanding) than when power is a solo affair.

2. It is not only important that team members have diverse skills and resources but that everyone knows what they are, so that they can be fully leveraged.

3. Internal power expressions among team members should shift as appropriate.

4. Team membership should be fluid, with members entering and exiting as necessary to meet shifting situations

source: 

The Riddle of Heterarchy: Power Transitions in Cross-Functional Teams

1. Federico Aime1, 
2. Stephen Humphrey2, 
3. D. Scott DeRue3 and
4. Jeffrey B. Paul4

http://aom.org/News/Press-Releases/Leadership-is-neither-a-matter-of-rank-nor-a-solo-affair,-study-finds.aspx

6 Reference Models for Shop Floor Control

http://www.home.zonnet.nl/azwegers/thesis/ch6.htm