SPARE PARTS INVENTORY OPTIMIZATION FOR AUTO MOBILE SECTOR

In this paper the objective is to determine the optimal allocation of spares for replacement of defective parts on-board of a usage. The minimization of the total supply chain cost can only be achieved when optimization of the base stock level is carried out at each member of the supply chain. A serious issue in the implementation of the same is that the excess stock level and shortage level is not static for every period. This has been achieved by using some forecasting and optimization techniques. Optimal inventory control is one of the significant tasks in supply chain management. The optimal inventory control methodologies intend to reduce the supply chain cost by controlling the inventory in an effective manner, such that, the SC members will not be affected by surplus as well as shortage of inventory. In this paper, we propose an efficient approach that effectively utilizes the Genetic Algorithm for optimal inventory control. This paper reports a method based on genetic algorithm to optimize inventory in supply chain management. We focus specifically on determining the most probable excess stock level and shortage level required for inventory optimization in the supply chain so that the total supply chain cost is minimized . So, the overall aim of this paper is to find out the healthy stock level by means of that safety stock is maintained throughout the service period. Keywords: genetic algorithm, optimization, Inventor

Environmental and Economic Benefits of using Multi-Echelon Inventory Control

Summary This master thesis evaluates the benefits of using multi-echelon control instead of single-echelon control of a multi-echelon inventory system. The multi-echelon inventory system studied in this thesis is a one-warehousemultiple- retailer inventory system. Multi-echelon inventory control is defined as a method to optimize the inventory system by taking the interdependencies between different stock locations in the system into consideration. Single-echelon control on the other hand is defined as optimizing each stock point in isolation and disregarding the interdependencies that exists. There has been extensive research in this area, and the fact that large potential cost reductions exist is well documented. However, little research has been performed to evaluate the environmental benefits that can be rendered by implementing multiechelon inventory control. The purpose of this master thesis is to evaluate the environmental and economic benefits of using a more advanced multi-echelon control method in a real case instead of the commercial single-echelon control method currently used. The hypothesis is that by fulfilling the fill-rates better, the amount of emergency orders can be reduced significantly, and by this also the total CO2-emissions can be reduced. The company studied is Lantmännen Maskin AB (LM) who provides their retailers in Sweden, Norway and Denmark with spare parts for agricultural machinery. The methodology used have been that of an operations research study where both mathematical models and simulations have been used. As a base model a commercial single-echelon model currently used at Lantmännen Maskin has been used, called SCP in this thesis. This model was compared to a more sophisticated multi-echelon model developed at Production Management, Lund University, Faculty of Engineering by Berling and Marklund (2012;2013), called MEM in this thesis. The approach of the project can be divided into five steps; first the data from the case company was gathered. Secondly, an existing simulation model was extended to fit the needs of this study. Thirdly, a stratified sampling was performed on the gathered data to find a representative sample of the case company’s items. Fourthly, the inventory system was optimized with SCP and MEM respectively. Finally, the results from the SCP-model and the MEM-model was simulated and compared. The results show that the average fill-rate was increased with 8.3% from 92.0% to 99.6%, the holding costs went down with 18.1% and the CO2- emissions were reduced with 57.0%. Further, the MEM model shows to be more consistent on achieving target fill-rate, whereas the SCP model varies a lot and delivers some fill-rates which are well below target and some that are above. Sensitivity analysis of the results concerning the CO2-emissions shows that for this case study the emergency orders sent by air do not affect the system very much. The reason is that the emergency transports by air are very few compared to the ones sent by truck. To really examine the benefits that could be achieved with the MEM model compared to the SCP model, a modified case set up was investigated where all emergency orders were assumed to be sent by air. In this case the reduction of CO2-emissions can be as high as 90%. Another important aspect found during this thesis concerning the CO2-emissions is that certain item attributes can make some items affect the CO2-emissions of the whole system in a non-proportional way. Two important factors were found, weight and mean demand. All CO2-emissions are linearly dependent on the weight, and consequently, this is a very important factor. But the second factor has even more influence. The reason for this is that if the mean demand for an item is high compared to other items then this item can have relatively many emergency orders even if the fill-rate is high. This was found during the study where one item, which had a high fill-rate, emitted CO2-emissions equivalent to 68% of the CO2-emissions of all of the studied items. Consequently, the conclusion from the results is that implementing the MEM model instead of the SCP model will reduce the environmental impact. Further, there are other aspects which are important to consider; firstly the MEM model will be more consistent on achieving target fillrates than the SCP model, secondly the reduction of CO2-will be greater in a system using air transport for emergency orders instead of land transport, and finally, the weight and mean demand are important aspects to consider if the environmental impact is to be reduced

Evaluation of a sustainable spare part distribution at Tetra Pak

Purpose The purpose of the report is to look into the effect of changing from air shipments to sea shipments at Tetra Pak Technical Service AB and the economical and environmental impact of such a change on the supply chain. Methodology The report is carried out by collecting the data regarding the different transportation modes in interviews with responsible persons within Tetra Pak and the transporter Geodis Wilson. The data is then simulated for general materials with suitable parameters and a general graph is generated from the simulations. The graphs are applied to the real life materials and a validation of the model is to be done. Conclusion This report shows that a maritime set up for stock refill between local and central warehouses in the affected routes are generally very interesting for heavy weight materials with high demands. There are several interesting materials even within TSAB (Tetra Pak Technical Service AB) but the spare parts business is not the most suitable area for sea transportation due to the low volumes and erratic VI materials. Despite this there are still enough incitements even within these materials to introduce a process to handle the few obviously interesting materials. Regarding the environmental impact (measured as the emission of carbon dioxide) it´s clear that sea transportation is a more sustainable alternative. But as long as the company policy is unclear regarding the value of reducing the impact or no targets are set to reduce the total impact it´s not feasible to include it as a cost in a separate decision as the one discussed in this report

Safety management of a complex R and D ground operating system

A perspective on safety program management was developed for a complex R&D operating system, such as the NASA-Lewis Research Center. Using a systems approach, hazardous operations are subjected to third-party reviews by designated-area safety committees and are maintained under safety permit controls. To insure personnel alertness, emergency containment forces and employees are trained in dry-run emergency simulation exercises. The keys to real safety effectiveness are top management support and visibility of residual risks

PLA Logistics and Sustainment: PLA Conference 2022

The US Army War College People’s Liberation Army Conference (PLA) Conference was held March 31 to April 2, 2022, at Carlisle Barracks, Pennsylvania. The conference focused on PLA logistics and sustainment. As the PLA continues to build and modernize its combat forces, it is important to examine if the capabilities meant to support combat operations are also being developed. Specific topics included: 1) China’s national-level logistics, including how China mobilizes national resources for the military and how it provides joint logistics support to the PLA Theater Commands; 2) the logistics capabilities of the different PLA services, especially the Army, Navy, and Air Forces; 3) PLA logistics in China’s remote regions, such as airpower projection in the Western Theater Command along the Indian border; and, 4) the PLA’s ability to sustain overseas operations at its base in Djibouti. Despite notable potential shortfalls and points of friction, the PLA has successfully sustained counterpiracy maritime operations for many years and conducted noncombatant evacuation operations well-distant from China. It is increasingly able to move forces across the vast distances of China and conduct large training exercises. Far more must be known about PLA sustainment and logistics before the hard questions about PLA operational reach and endurance can be answered.https://press.armywarcollege.edu/monographs/1954/thumbnail.jp