Performance Analysis and Optimization of Assemble-to-Order Systems with Random Lead Times

  • Authors:
  • Jing-Sheng Song;David D. Yao

  • Affiliations:
  • -;-

  • Venue:
  • Operations Research
  • Year:
  • 2002

Quantified Score

Hi-index 0.00

Visualization

Abstract

We study a single-product assembly system in which the final product is assembled to order whereas the components (subassemblies) are built to stock. Customer demand follows a Poisson process, and replenishment lead times for each component are independent and identically distributed random variables. For any given base-stock policy, the exact performance analysis reduces to the evaluation of a set ofM/ G/8 queues with a common arrival stream. We show that unlike the standardM/ G/8 queueing system, lead time (service time) variability degrades performance in this assembly system. We also show that it is desirable to keep higher base-stock levels for components with longer mean lead times (and lower unit costs). We derive easy-to-compute performance bounds and use them as surrogates for the performance measures in several optimization problems that seek the best trade-off between inventory and customer service. Greedy-type algorithms are developed to solve the surrogate problems. Numerical examples indicate that these algorithms provide efficient solutions and valuable insights to the optimal inventory/service trade-off in the original problems.