The BB system, a relay-type, self-regulating and balancing manpower system
developed by Bartholdi and Eisenstein (1996) is hypothesised to target and significantly
improve these operational functions on a real time basis. Unlike most studies (for example,
Wang et al. 2007) which utilise optimisation techniques with rather static operational
characteristics, our study focuses on decision rules in an unforeseeable environment with
few known and deterministic assumptions. The BB system’s dynamic work allocation and
pre-emption techniques have been successfully implemented at order picking in
warehouses and assembly lines at manufacturing plants (Villalobos and Mun˜ oz 1999
and Bischak 1996, Bartholdi et al. 1999, Bartholdi et al. 2001, Mun˜ oz and Villalobos 2002,
Villalobos et al. 2006). In the BB system, each worker carries a product towards
completion. For instance, in a serial assembly line when the last worker finishes his
product, he sends it off and then walks back upstream to take over the work of his
predecessor (pre-emption). Similarly, the predecessor walks back and takes over the work
of his predecessor until the worker manning the first work station on the line (traditionally
the less experienced) introduces more raw material into the line (dynamic work allocation).
If the workers are sequenced from slowest to fastest, then they will gravitate to a division
of work that maximises throughput.