#This principle valued the discretionary rather than the prescribed part of work roles (Jaques, 1956). - Eric Trist

The outstanding feature of the social pattern with which the pre-mechanized equilibrium was associated is its emphasis on small group organisation at the coal face. [Indeed], under these conditions there is no possibility of continuous supervision, in the factory sense, from any individual external to the primary work group.

The advantage of placing responsibility for the complete coal-getting task squarely on the shoulders of a single, small, face-to-face group which experiences the entire cycle of operations within the compass of its membership. [And furthermore], for each participant the task has total significance and dynamic closure .

Every time the cycle is stopped, some 200 tons of coal are lost. So close is the task interdependence that the system becomes vulnerable from its need for 100 percent performance at each step.