Kapitalrationalisering i materialanskaffningsprocessen på Huskvarna Prototyper AB

Sammanfattning: Huskvarna Prototyper AB started as a producer of prototypes, but has, during the latest years also started producing small series of products. This development of becoming a batch producer has brought about new strategies for material supply and for controlling inventory. The need for new strategies is also what initiated this work. The purpose of the work is to analyze the company’s material supply methods, and study if there are any possibilities to improve the methods that are used in the present situation, to reduce the cost of the raw material inventory. A general mapping of the company, and a more profound mapping of customers and items, generates a helicopter view of the company and its flows and processes. From the description of the current situation, an analysis of the customers and items is carried out. In the analysis, the customers and items are divided into groups through ABC-analysis. A profound analysis is made on a few items to find similarities considering throughput time, cost of material, frequency of delivery and volume. The items related to the customers Preciform AB and Henjo Plåtteknik AB have been analyzed further, and cover times have been calculated for the materials. The cover time analysis of the items of Preciform AB shows stock levels for the years of 2007 and 2008, which are considerably higher than required. An apparent problem in the methods of materials supply is shown and a proposal of a method for controlling stock levels and materials supply is using cover time. Using this also requires batch sizing methods, and the method periodic order quantity, is recommended. In this method of batch sizing, the time between the orders is calculated, and the quantity of each order is based on the demand of the period. One important aspect is continuous follow-up of the stock levels, to control the cover time not being exceeded. Analysis of Henjo Plåtteknik AB’s materials shows stock levels which are not securing more cost of inventory than necessary in most stock-taking intervals. The raw material of this item is also used for producing other items, which have not been analyzed. Thus, the analysis of this material is not absolute. Inventory control using cover time is applicable for other items within the same group as Preciform AB’s items, but also for items in other groups. Conclusions have been made for low frequency materials and low value materials as well. Low frequency material with high or medium high value should be controlled with lot for lot batch sizing, to avoid tying up capital in stock. Low value materials are appropriately controlled using fixed order quantity. An important issue of this group is to not spending too much time working with different methods of batch sizing, since the low value of materials does not provide a significant contribution to cost of inventory. The simplicity of the methods of material supply is considered important by the authors. Visualization of stock levels, and how cover time and cost of inventory is affected by actual actions, is important for the acknowledgement of the methods from the employees.