Abstract:
One of the classic problems in industrial engineering is the buffer allocation
problem. The objective of the buffer allocation problem is to maximize some line
output, typically throughput, through the allocation of buffers throughout the
production line. Previous work in this area has focused on either determining
general design rules or developing heuristics to determine optimal buffer
placement. Most of this work was done on production lines which were assumed
to have an unlimited supply of jobs to the first workstation and an unlimited
storage space after the last workstation (open production lines).
The purpose of this research was to study buffer allocation in closed production
lines and focus on the validation and development of general design rules for
buffer placement. Balanced and unbalanced lines were studied with workstations
representing manual stations, and then with workstations representing automated
machines.
The general approach taken was to first identify an existing buffer allocation rule
established for open lines and then determine the corresponding rule for closed
production lines. Next, a set of experiments were designed to test the closed
production line design rule. Finally, the design rule was validated, modified, or
reformulated.
The findings of this research indicate that an even buffer allocation is optimal for
balanced closed production lines. It also showed similar behavior to open
production lines when a bottleneck is present, but the effect of the bottleneck is not
as strong. Also, differences between reliable and unreliable lines were observed.
Finally, the rules developed seemed to be consistent for short lines as well as long
ones.
Several of the rules developed in this research can be utilized immediately in the
design of closed production lines. Also, because of the lack of literature on closed
production lines, it will serve as a good first step into the understanding of the role
of buffers in closed production lines.
