Inventory Control -at Maintenance Unit Tetra Pak in Lund

Abstract: Maintenance Unit is one out of many divisions at Tetra Pak in Lund. They are producing spare parts for the dairies to enable a quick and easy way of serving the packaging machines. When assembling the spare parts, approximately 30 % of the components used are reconditioned components, lowering the price for the spare part. Today they have 1000 different spare parts in their product portfolio and due to this they have a warehouse with approximately 6000 different components. The objective of this master thesis is to improve the inventory control system at Maintenance Unit. The overall objective can be broken down into two parts. The first is to create a model for controlling and optimising the safety stock of new components. The second is to create a model for joint inventory control of new and reconditioned components. The thesis can be seen as a quantitative study since the majority of the information is gathered from Maintenance Units’ business system. It contains some elements from a qualitative study such as interviews. These have been conducted to verify the information from the business system and to gather new information. The majority of the theories used are well known within the subject of inventory control such as ABC inventory analysis. These theories are complemented by other less known theories. There are not many papers covering the subject remanufacturing and reverse logistics. Therefore the formulas used in the part concerning reconditioned articles had to be deduced. The steps required to reach the conclusion were the following: categorisation of the components into homogenous groups with consideration to different factors. determine the distribution for the demand. establish different fill rates and the holding costs associated with these. The results are that the components can be categorised in several dimensions into homogenous groups with a certain fill rate. These groups can be visualised by cubes where the axles are the dimensions in which the components are categorised by. It is up to the decision maker to determine the appropriate fill rates for the different groups.