Model Pengambilan Keputusan Inventori dalam Sistem Logistik Tiga Eselon

Abstract

This thesis addresses an integrated inventory and routing problem in a threeechelon logistics system, which consists of a supplier, a central warehouse and a group of retailers. The inventory decision of each member and the routing decision among members of the system are made simultaneously, with the objective of minimizing the overall average cost of the system. A strategy named fixed partition and power-of-two (FPPOT) is proposed for the considered problem and a variable large neighborhood search (VLNS) algorithm, which is a special case of variable neighborhood search (VNS) algorithm, is developed. The efficiency of the strategy as well as the algorithm is illustrated by comparing computational results with a lower bound. The advantage of the proposed VLNS algorithm is further shown by getting better results for the problems in a two-echelon logistics system, which have been solved by a Tabu Search algorithm.

Tesis ini mengkaji masalah persediaan dan routing terpadu pada sistem logistik tiga-echelon, yang terdiri dari pemasok, gudang pusat dan kelompok pengecer.Keputusan persediaan masing-masing anggota dan keputusan routing di antara anggota-anggota sistem diambil secara simultan, dengan tujuan meminimalkan biaya rata-rata keseluruhan sistem. Strategi yang disebut partisi tetap dan kekuatan-dua-pihak (fixed partition and power-of-two [FP-POT]) diajukan untuk masalah yang dikaji dan dikembangkan algoritma pencarian neighborhood Variabel (VLNS), yang merupakan kasus khusus dari algoritma pencarian neighborhood variabel (VNS) . Efisiensi strategi dan juga algoritma diillustrasikan dengan membandingkan hasil perhitungan dengan batas bawah. Kelebihan algoritma VLNS yang diajukan ditunjukkan lebih lanjut dengan memperoleh hasil-hasil yang lebih baik untuk masalah pada sistem logistik dua-echelon, yang diselesaikan dengan algoritma Tabu Search.