ABC电脑分析：库存管理基础【外文翻译】

外文翻译

原文

COMPUTERIZED ABC ANALYSIS: THE BASIS FOR INVENTORY

MANAGEMENT

Material Source: Author: Chao-Hsian Chu, Ying-Chan Chu ABSTRACT

This paper presents a microcomputer- based ABC analysis for inventory management. The conceptual framework and technical issues involved in the design of the system are discussed. The program is designed to be user-friendly and is full of many informative functions, such as, pause for reaction, full screen, menu selection, error checking, warning, correction, and graphic display.

INTRODUCTION

ABC analysis, also known as Pareto principle or management by exception tool, has long been used in industries for various IE applications (quality control), cost reduction, work measurement, method improvement, inventory management etc., for instance. The use of ABC analysis in inventory management started from the early 1950's and has become the basis for the management and control of inventory systems.

Three problems associated with the traditional ABC analysis: (1) how to select a suitable measuring criterion, (2) What is the most appropriate numbers of category, and (3) how to classify items into classes. In this paper our focus will be on the classifying rules with assumptions that annual dollar usage is the criterion and the suitable numbers of category is three. The principles and techniques presented however can be applied to other measuring criteria with different number of grouping.

Although 20-80 rules provides an approximate guideline for the classification, people using this rule always encounter difficulty, due to its ambiguity and subjectiveness. The laborious work involved in the analysis also prevents its broader applications. A computerized system with Japanese's classifying algorithm not only can largely simplify the analysis but also make the task of classification more objectively.

ABC PHENOMENA

ABC principle has been used in the field of economics for many years, and is

often called praetor principle or Lorenz law. The principle states that a small fraction of items accounts for a large amount of the total value or activity. Many of our real life cases have this type of phenomenon. Some examples from different areas are given in Table 1.

•A few components have extremely long lead time.

•A few percent of the orders accounts for the bulk of the dollars spent.

•A few days have most of the outgoing or incoming orders.

•A few vendors cause most of the delays.

•A few Items are holding up most of the backorders.

•A few customers give a company most of its orders.

•A few salespersons sell most of the products.

•A few percent of customers accounts for the bulk of the credit losses and the bulk of unjustified returns.

•A few products generate most of the profit.

•A few products go through the service department.

•A few operations have most of the quality problems.

•A few percent of quality characteristics accounts for the bulk of the customer complaints, scraps, and reworks.

•A few cities have most of the population.

PROCEDURE FOR ABC ANALYSIS

Selecting a suitable measuring criterion and classification rules forms the basis of an ABC analysis. In practice, most of the companies used annual dollar usage, i.e., unit price time’s annual demand as criterion, and the so called 20-80 rule as an approximate guideline for inventory classification. Several steps are required for an ABC analysis:

1. Select a suitable measuring criterion. The criterion selected normally depends on the purpose of the study. For example, defective rate is often used for quality control purpose; 70% of total sales is used for marketing statistics; and the annual usage value is widely used for inventory management.

2. Collect and validate the required data. All of the data collected must be validated and the units of the data must be consistent.

3. Perform the necessary computations. For inventory management application these include the following:

• Calculate annual usage value A, where:

Annual usage value A = Unit price (p) Annual ⅹ Demand (D)