BATCH ORDERING INVENTORY MANAGEMENT UNDER THE MIXED DEMAND INFORMATION: A CASE STUDY

Yıl 2020, Cilt: 8 Sayı: 3, 666 - 677, 03.09.2020

Muzaffer ALIM Patrick BEULLENS

https://doi.org/10.36306/konjes.599332

Cited By: 1

Öz

This study is concerned with analysing the past demand data and development of an
inventory model with demand arising from deterministic which is known in advance and random sources
simultaneously. Two different shortages are created for each demand type and in order to prevent model
to backlog the deterministic demand, very high shortage cost is given for deterministic demand. The
numerical value of the parameters are obtained from a real case which the inventory system of an
information and technological organization of a university. The main difference of this study from the
previous studies is that the order amount must be in palette quantity for a deterministic and stochastic
demand inventory problem. Under this constraint, an inventory model is developed and tested with
several datasets. Assuming lead time as constant, the value of deterministic demand present in the system
and impact of palette constraint are investigated. These investigations are compared with the status quo
in the case study. It has seen that the palette quantity behaves as safety stock for high level random
demand. Recommendations based on the impacts of advance demand information, lead time and pallet
quantity are presented in terms of changing in ordering costs, holding costs and service level.

Anahtar Kelimeler

Inventory model, batch ordering, deterministic and stochastic demand, mix integer programming

Karışık Talep Bilgisi Kapsamında Toplu Sipariş Envanter Yönetimi: Bir Durum Çalışması

Öz

Bu çalışma, geçmiş dönem talep bilgisinin ve önceden bilinen deterministik ve rassal talep bilgisinin
birlikte bulunduğu stok sistemlerinin analizini konu almaktadır. Herbir talep bilgisi için iki farklı talebi
karşılayamama maliyeti belirlenmiş olup deterministik talebe verilen yüksek talep karşılayamama
maliyeti bu tip talebin zamanında karşılanmamasını oldukça güç hale getirmektedir. Kullanılan veriler
bir üniversitenin bilgi teknolojilerinden sorumlu olan birimden alınmıştır. Bu çalışmanın literatürdeki
diğer çalışmalardan farkı aynı anda hem deterministik hem de rassal talep altında sipariş miktarının palet
cinsinden olmasıdır. Bu kısıt altında, bir stok modeli geliştirilmiş ve farklı veriler altında sayısal olarak
test edilmiştir. Sabit tedarik süresi varsayımı altında, deterministik talebin değeri ve paletle sipariş
kısıtının etkileri ölçülmüştür. Bu ölçümler, mevcut durumla kıyaslanmıştır. Paletin içerik miktarının
yüksek seviyedeki rassal talep için güvenli stok olarak davrandığı gözlemlenmiştir. Değişen sipariş
maliyeti, stok tutma maliyeti ve hizmet seviyeleri altında ön talep bilgisi, tedarik süresi ve palet miktarının
etkileri üzerine önerilerde bulunulmuştur.

Anahtar Kelimeler

Envanter modelleme, yığın sipariş kısıtı, deterministik ve rassal talep, matematiksel modelleme

Kaynakça

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