THE AGILITY OF BUCKET BRIGADE PRODUCTION LINES

Bucket brigade production lines can be configured to be spontaneously self-balancing. This confers an agility that is inherent, guaranteed, quantifiable, and stronger than conventional use of the term. We discuss the practical implications.

In a "bucket brigade" production line there are fewer workers than stations. Workers carry product from station to subsequent station; then, when the last worker finishes an item, he returns to take over the item of his immediate predecessor, who returns to take over the work of his predecessor, and so on, until the first worker on the line starts a new item.

The idea is that, by abolishing fixed work zones, workers can locally adjust how work is shared and so improve the instantaneous balance. However, we have discovered an even more powerful effect: If the workers are sequenced from slowest to fastest, then global balance will spontaneously emerge and the line will achieve the maximum production rate [Bartholdi and Eisenstein, 1996; Bartholdi, Bunimovich, and Eisenstein, 1995; Bartholdi, Bunimovich, and Eisenstein, 1996; Bartholdi, Eisenstein, Jacobs-Blecha, et al., 1995]. It is this inherent, constant attraction to balance that makes bucket brigade production lines agile, by which we mean that they allow manufacturing resources to be quickly and easily reconfigured. In fact, bucket brigade lines are agile in a stronger sense than that of conventional usage: Bucket brigades can spontaneously adapt to changing circumstances. This means that management does not have to plan or direct a response. In fact, management need not even recognize that there is a problem! Let us look at some examples.