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

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.

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

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

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