  This paper investigates the reduction of variance associated with a
simulation output performance measure, using the Sequential Sampling method
while applying minimum simulation replications, for a class of JIT (Just in
Time) warehousing system called crossdocking. We initially used the Sequential
Sampling method to attain a desired 95% confidence interval half width of
plus/minus 0.5 for our chosen performance measure (Total usage cost, given the
mean maximum level of 157,000 pounds and a mean minimum level of 149,000
pounds). From our results, we achieved a 95% confidence interval half width of
plus/minus 2.8 for our chosen performance measure (Total usage cost, with an
average mean value of 115,000 pounds). However, the Sequential Sampling method
requires a huge number of simulation replications to reduce variance for our
simulation output value to the target level. Arena (version 11) simulation
software was used to conduct this study.
