Thesis Defense :: Some Generalizations of Bucket Brigade Assembly Lines
We generalize the idea of self-organizing bucket brigade assembly lines in several directions. These include a generalized model that permits chaotic behavior, an adapted protocol for complex assembly networks, and a more detailed model for order-picking along an aisle with multiple job sources.
Many simple, deterministic systems may exhibit extremely complicated behavior (called chaotic behavior). The variability induced by the chaotic behavior of a system can be so large that the output of the system is effectively random. This variability may severely deteriorate the performance of a system in a manufacturing environment. By studying the dynamical behavior of the system this chaotic behavior may be avoided with a proper system configuration. We study a generalized model of bucket brigades in which workers walk back with finite velocities and are allowed to pass each other. Based on this model, we have formally proved that the dynamics of a purely deterministic bucket brigade assembly line can be chaotic and may induce large variability if it is improperly configured.
We present a sufficient condition to avoid this chaotic behavior and to make the bucket brigade self-balanced.
The bucket brigade protocol can be adapted to assembly "trees". In a network of subassembly lines in which subcomponents are produced and are then successively combined to make the final product, balance becomes more difficult to achieve as it requires that all subassembly lines be synchronized to produce at the same rate. We show how to adapt the bucket brigade protocol of work-sharing so that balance emerges spontaneously.
We have also generalized the idea of bucket brigades to flow lines with multiple job sources. This work is motivated by the order-picking operation in a major distribution center in which customer orders arrive arbitrarily in time and are introduced into the system at multiple points along an aisle. We compare the performance of an adapted bucket brigade protocol with the order-picking policy currently adopted by the distribution center.
- Workflow Status: Published
- Created By: Barbara Christopher
- Created: 10/08/2010
- Modified By: Fletcher Moore
- Modified: 10/07/2016