Simulation Verifies Queuing Program for Selecting Loader‐Truck Fleets

Abstract

Proper equipment selection can yield substantial savings in time and cost. MicroCYCLONE simulation package is used to verify the FLEET queuing program. FLEET models multiloader‐truck systems using exponential distribution at steady state. A few FLEET assumptions are redefined to closely model real‐world construction processes. Graphical solutions illustrate effects of the cycle‐time modeling and transient state on multiloader‐truck fleet selection. FLEET is shown to be an accurate model of the steady‐state, multiloader‐truck process if exponential distribution did accurately fit load‐ and travel‐time distributions. But, erlang or beta distribution more closely fits actual load and travel times in construction. Modeling load and travel times of loader‐truck fleets with exponential, instead of beta, distribution results in underestimation of production and overestimation of unit cost by 4–7%. Simulation results of a more accurate model that uses beta distribution and considers transient state, in addition to steady state, indicate that multiloader‐truck fleets may experience a 4–5% production increase and unit‐cost decrease compared to FLEET results.