库存管理系统 - 一种生产要素同时规划与生产模式备件.doc

库存管理系统 - 一种生产要素同时规划与生产模式备件彼得亚雷Cyplik，安斯基哈达什物流系统部波兹南物流学院Estkowskiego 6街61-755 Poznan，波兰Abstract-This paper presents, proposed by the authors, application classical models of stock replenishment in production planning model with simultaneous production of identical components for the need of own assembly and as spare parts in machine industry plants. The goal of the thesis was to elaborate a production planning model which would allow to combine all demand sources within one production schedule and to decrease spare parts stock with simultaneous production of identical components (spare parts, subassemblies) for the need of own assembly and as spare parts. The proposed production planning model has been based on the classical stock management theory and material requirement planning methods. It results in merging production management and stock management in a one coherent material flow management system. The research was done in GRUNDFOS POMPY Ltd. Company. RUNDFOS is one of the biggest pump producers in the world. The model has been verified through its implementation and resulted in a decrease of spare parts stock by nearly 50%.摘要，本文提出了作者，同时应用规划与生产相同成分的自己的组装需要及在机械工业设备备件的库存补货模型古典模型的生产。该论文的目标是制定生产规划模型，允许在一个结合生产计划，所有的需求来源，并减少与生产相同成分的同时库存备件（零件，组件的自己组装的需要）和备件。拟议的生产规划模型，基于传统库存管理的理论和物料需求计划方法。在合并在一个连贯的物质流管理系统的生产管理和库存管理，它的结果。该研究是在格兰富POMPY有限公司公司。 RUNDFOS是世界上最大的泵生产商之一。该模型已核实通过实施该计划和今后一个备件库存减少，导致了近50。I. INTRODUCTION一， 导言The material requirement planning at the beginning of its existence was treated as alternative of standard methods of stock management. The evidence of it can be the definition in “Terminology in Logistics” European Logistics Association 9, which material requirement planning in stock planning and management describes as the approach to stock planning and management based on two logistics activities:在其存在的物料需求计划开始就被视为对库存管理的标准方法的选择。在这方面的证据可以成为“的定义，物流术语”欧洲物流协会9，其中库存物料需求计划的规划和管理形容为股票的规划和管理办法的两个物流活动为基础：1) The simulation of future stock quantity done on the basis of the currant stock level and anticipated demand or scheduled changes of stock level.2) Calculating the material and goods requirement on a lower level on the basis of product structure. These two activities are taken repeatedly on each level of theproduct complexity. In this way the entire material requirement is defined on the basis of the final product demand. In the previous issues of the dictionary this definition of material requirement planning preceded the one which in the recent issue is listed as first. Another evidence of such approach to the idea of materialrequirement planning is a classic book by O. Wrigh “Production and inventory management in the computer age”. The publication of this book, in fact, introduced the theory of material requirement planning, preparing the ground for another classic book by J. Orlicki. 81） 未来股票对葡萄干库存水平和预期的需求或库存水平变化的基础上进行预定量的模拟。2）计算就关于产品结构的基础上低层次的物质和物品的要求。这两项活动是采取反复的每个级别产品的复杂性。在这整个物质的要求是对最终产品需求的基础上确定的方式。之前，在词典的这种材料的规划需求定义上的问题之一，在最近的问题是第一家上市。这种做法的另一个对证据材料的想法需求计划是一个由澳蓣经典著作“生产和库存管理计算机时代”。这本书的出版，事实上，介绍了物料需求规划理论，准备再由J. Orlicki经典书的理由。 8II. THE ASSUMPTIONS OF THE PRODUCTION PLANNING MODEL:二。生产规划模型的假设：The production planning model with simultaneous production of identical components for the need of own assembly and as spare parts should be inseparable with the model of stock determining in machine industry plants. This means that there is a mutual correlation between the method of production and the adopted system of stock replenishment. It is particularly crucial in plants with the developed distribution network of final products. The adopted system of stock replenishment in the links situated the closest to the client is strictly connected with sales planning, which in turn influences the production planning directly. The purpose of working out the model was to reduce the level of goods on hand, thus it was justified to reorganize the process of stock replenishment in their decoupling point. Accurately determined time and size of the order in this point reflects in working out such a production planning which meets the expectations that were assumed in the purpose.The basic assumptions of the model include:与同时生产的需要自己组装部件和相同的生产规划模型的零件应与在机械工业厂房模型确定的股票是分不开的。这意味着，这两者之间的生产方法和股票采用的制度，相互补充的关系。这是特别重要的植物与最终产品的开发销售网络。补充的股票位于通过向客户联系最密切的联系制度，严格的销售计划，这反过来又影响了生产计划直接。在制定该模型的目的是降低产品手头的水平，因而是合理的重组在其解耦点的库存补充过程。准确地确定时间，在这一点订单规模，开展这项生产计划，满足了那所期望的目的，承担的工作体现。该模型的基本假设包括1) The production planning is done based on the material requirement planning method and is computer supported. The method of material requirement planning is applied to production planning from the moment of generating spare parts requirement in the decoupling point.2) The spare parts demand is treated as independent demand. Repeated production aimed at a diverse group of receivers is assumed. The producer has a limited influence on the final products users, thats why the failure of particular parts take place at random.3) The spare parts stock in the decoupling point results from:- Uncertainty of demand.- Uncertainty of deliveries- The necessity of maintaining production continuity.4) The main schedule was worked out in the make to stock or mixed versions. In the make to stock option planning takes place exclusively according to the requirement forecast. In the mixed version confirmed orders are taken into account as well. Such an assumption enables considering production of the same products, both in a standard form and in adjusted to individual orders of customers.1）生产计划的基础上完成的物料需求计划方法，是计算机的支持。在物料需求计划方法适用于从生产计划产生的去耦点零配件需求的时刻。2）零件的需求是独立的要求处理。重复生产在一群不同的接收器为目的的假设。生产者有一个对用户的最终产品的影响力有限，这就是为什么对特定地区采取随机故障发生。3）零件的去耦点结果股票：- 不确定性需求。- 不确定性的分娩- 在保持生产的连续性的必要性。4）主要日程是制定出来的股票或作出混合版本。在股票期权作出规划发生完全符合要求的预测。在混合版本确认订单是考虑也。这样的假设可以考虑根据同一产品的生产，在一个标准的形式都和调整，以客户个性化的订单。III. THE MODEL OF PRODUCTION PLANNING三。生产计划模型That model of production planning with simultaneous production of identical components for the need of own assembly and as spare parts based on the choice of an appropriate method of stock replenishment in the decoupling point consists of five consecutive stages:1) The classification of spare parts range.2) Identifying the decoupling point in the company.3) The analysis of spare parts stock in the decoupling point4) The choice of appropriate system of spare parts stock replenishment adjusted to the condition and type of the company.5) Parameterization of the worked out solution.这种生产计划与生产同步相同部件自己组装的需要和对补充的股票选择适当的方法中基于解耦点备件模型由连续5个阶段：1）范围零件分类。2）确定公司内的去耦点。3）库存备件的解耦点分析4）备件库存补货系统，选择适当的调整的情况和公司的类型。5）参数化方案的制定。A. The classification of spare parts rangeA：零件分类范围The heterogeneity of spare parts and their diversity require dividing them into categories and assigning appropriate parameters to them. The categories should comprise a group of ranges similar to each other with a complementary characteristic consistent with the accepted criterion of division. Individual categories are of different importance from the point of view of the corporate policy concerning the level of customer service. The most common method of product range division is the ABC method (also called Pareto method). The authors suggest that besides usual group A (about 20% of all items which generate about 80% of sales), B (about 30% of all items which generate about 15% of sales) and C (other items), a sub-group D should be selected from group C and this group should comprise all items for which during the analysis no issue (sale) was observed and for which only returns to the warehouse were observed. John Schreibfeder ranks items classified in this way as X 7.备件的异质性和多样性要求分为三类，并分配适当的参数给他们。类别应包括的范围相似，另一组有互补的特点与分裂接受的标准是一致的。个别类别有不同的重要性，从公司有关客户服务水平的政策观点。该部门的产品范围最常用的方法是ABC法（也称为帕累托方法）。作者建议，除了通常的A组（所有项目将产生约80的销售额约20），B级（约30的物品产生的销售额的15）和C（）其他项目的一个分D组应选择从C组，这组在分析其中应包括所有项目的任何问题（销售），观察和只返回到仓库观察。约翰Schreibfeder队伍列为此方法为X 7个项目。From the point of view of particular spare parts parameterization it is not sufficient to apply only one criterion in allocating them to the above groups. The accepted criterion of spare parts allocation to specified groups does not reflect how important they are for the final customer and what is the issue (sale) frequency.从具体参数化零件的角度来看是不够的分配适用于上述这些集团唯一标准。在分配的部件接受的标准到指定的群体并不能反映他们是多么重要的最终客户，什么是问题（销售）的频率。It seems obvious that there should be a difference between elements of esthetic character (e.g. a sliver gearshift lever handle) and elements crucial for reliable functioning of the final product. A method ideal for such product range division is CVA analysis (Customer Value Added) which represents a more subjective approach than the quantitative ABC analysis. According to the CVA principle the following groups are identified:1) Products of the highest priority (always on the stock) - which are later referred to as VIP (very important products).2) Important products (some small stock shortages are acceptable) - IP (important products).3) Products of medium priority (temporary shortages are acceptable) - MIP (products of medium importance).4) Products of low priority (they are needed but shortages can happen) - LIP (products of little importance).The allocation of particular spare parts to one of the group according to the ABC analysis (regardless of the accepted either quantitative or qualitative criterion) and to one of the listed about groups of CVA analysis conditions the possibility of their correct parameterization which is a crucial component of the suggested production planning model.The last criterion which determines spare parts product range division is the frequency of spare parts issues (sale). This classification is conventionally called 123.很显然的，应该有美学特征之间的差异因素（如银换档杆手柄）和最终产品的可靠运行的关键因素。对这种产品范围划分方法的理想是脑血管意外分析（客户增值），该数量比ABC分析比较主观的方法。根据脑血管意外以下组的原则确定：1）最优先的产品（总是在股票） - 这是后来被称为贵宾的（非常重要的产品）。2）重要产品（一些小的股票不足是可以接受的） - IP地址（重要产品）。3）中优先（暂时短缺是可以接受的产品） - 按揭保险计划（产品中）的重要性。4）低优先级产品（在有需要，但可能会发生短缺） - 口红不太重要（产品）。特定零件分配给该小组的一按ABC分析（不论接纳了定量或定性标准），并列出对脑血管意外的分析条件下的正确参数可能是一个重要组成部分的群体之一所建议的生产规划模型。最后一个标准的确定备件产品范围划分的备件问题（销售）的频率。这一分类是传统所谓的123。B. Identifying the decoupling pointB.识别的解耦点The location of the decoupling point (defined individually for each identified group of spare parts) indicates the relation between the suppliers lead time and the time of production cycle. In case of short suppliers lead time in comparison to the time of production cycle, there is a tendency to shift the decoupling point to the right; this is to the area of physical distribution. When, on the other hand, the required suppliers lead time is relatively long, and the observed demand is specific and irregular, a more advisable place for the decoupling point is the area of production, which means closer to raw materials and components.的去耦点的位置（界定每个零件的一群个别）表示，供应商之间的准备时间和生产周期时间的关系。在短期供应商相比，生产周期的时间而言，有一种倾向转移脱钩指向正确的，这是对物流领域。当，另一方面，所需供应商的准备时间比较长，以及观测的需求是具体的和不规则，为解耦点更为适宜的地方是生产领域，这意味着接近原材料和零部件。C.The analysis of spare parts stock in the decoupling pointC.的分析解耦点的备件库存The stock analysis method applied in the model makes use of standard, frequently described in literature, techniques. The authors of this paper choose and determine the sequence of them for the purpose of achieving the goal of the described model. The most important techniques of estimating the spare parts stock level in the decoupling point include:1) The indicator analysis of spare parts stock.2) The structure analysis of spare parts stock.股票分析方法，在模型中的应用使使用的标准，经常在文学，工艺描述。本文的作者选择并确定它们的序列为实现该目标的目的，模型描述。估算备件的库存水平解耦点最重要的技术包括：1）库存备件指标分析。2）备件库存结构分析。One of indicators often applied to estimate the stock level is its size (expressed in quantity, mass, volume) or its value. It is an absolute measure and it should be first of all used to carry out a running inspection, to compare with assumed quantities or with data from the past. Absolute measures (although they are easy to calculate) are usually not sufficient to estimate the stock level. This is the reason why to the indicator analysis of the spare parts stock level the author decided to apply relative measures concerning both the stock (cycle and average) and the demand. Such indicators are:1) Stock Turnover - is the quotient of the value of material issued in a particular time and the average value of their stock at the same time.2) Stock Cover - is the quotient of the average value of the stock in a particular time and the value of material issues at the same time. 指标人们经常用来估计股票水平的大小（以数量，质量，体积）或其价值。这是一个绝对的措施，应该首先用来进行运行检查，以比较承担的数量或从过去的数据。绝对措施（尽管它们很容易计算），往往不足以估计存货水平。这就是为什么到备件库存水平，提交有关决定，同时申请股票（周期和平均）和需求相对措施，指标分析原因。这些指标包括：1）股票成交量 - 是在特定时间发行商和物质价值，同时其股票的平均价值。2）库存封面 - 是一个在特定的时间商对股票的平均价值，同时对重大问题的价值。The indicator analysis must be treated as an introduction to deeper analysis connected with determining the stock structure. The detailed stock estimation must consider its dependence on the accepted customer service level, the time of stock renewal cycle and its changeability. Demand variation is another crucial element. Taking up a stock structure analysis it is necessary to identify the quantity of economic stock understood as an average stock kept in a tested time on a particular product range. Economic stock according to can include:1) Safety stock.2) Cycle stock.3) Surplus stock (can occur).该指标分析必须被视为一个更深层的分析确定股权结构连接的介绍。详细的股票估计要考虑接受的客户服务水平的依赖，股票更新周期和变性时间。需求的变化是另一个重要因素。到了股权结构分析，有必要确定在对某一产品系列进行测试的时间保持着平均股价理解经济库存量。根据经济股票可以包括：1）安全股票。2）周期的股票。3）剩余股票（发生）。The main function of the safety stock is securing against the demand variation during the replenishment lead time (delivery). Creating the stock enables to avoid after effects of not meeting customers demand.The cycle stock is the quantity of stock which is in permanent turnover and is understood as a half of an average size delivery.的安全库存的主要职能是对安全的需求变化，在补充的准备时间（交付）。股票，使创建后，以避免不符合客户需求的影响。该周期股票，股票的数量，这是永久的营业额，并作为一个普通大小的交付一半的理解。The most unwelcome in the stock structure is the surplus stock, keeping of which is not justified and only generates costs.The analysis of spare parts stock in the decoupling point is carried out on the basis of current values of identified elements which include:最不受欢迎的股权结构是多余的库存，其中没有理由是一致的，只是产生的费用。在股票备件解耦点进行了分析，对确定的因素，其中包括现值的基础上：1) The accepted level of customer service for particular product ranges.2) The accepted model of spare parts stock replenishment.3) The demand profile.1）客户服务接受特定的产品范围的水平。2）备件库存补货接受的模式。3）需求配置。D. The choice of an appropriate replenishment of spare parts stock adjusted to the conditions and type of a companyD中选择一个合适的备件库存补充调整的条件和类型的公司The choice of an appropriate replenishment of spare parts stock in the decoupling point is one of the elements determining the production plan. Due to the assumption which says that requirement is independent of spare parts, out of all known from literature models of stock replenishment one of standard models of stock replenishment has been accepted for further analysis - tailored to the conditions of the company or to the “lot for lot” model一个零件的股票在适当补充解耦点的选择是决定性的生产计划的内容之一。由于假设，认为这一要求是独立的备件从所有，从股票的股票补充标准模型的补充一著名文学模式已被接受进一步的分析 - 针对公司的条件或“地段对很多“模式TABLE 1METHODS OF COVERING THE REQUIREMENT FOR SPARE PARTS ASSIGNED TO PARTICULAR CATEGORIES ACCORDING TO ABC, 123 AND CVAANALYSES表1覆盖备件的方法分配数量的要求，某些类别根据ABC，123和CVAANALYSESThe appropriate model of spare parts stock replenishments can be different for each spare part that is why it has to be chosen for each item individually. Due to the possibility of a huge number of items two major determinants have been identified to choose the stock replenishment model:备件的库存补给适当的模式可以有不同的每个零部件，这就是为什么它必须对每个项目单独选择。由于两个主要因素已经确定选择补充库存模型中的项目数量庞大的可能性：1) Meeting the general assumptions for standard models stock replenishment.2) Assigning a particular product range to one of the groups based on the spare parts classification.Table1 presents how to choose an appropriate method of covering requirement in each of distinguished categories. The table includes the model of stock replenishment described as “to order”. It should be interpreted the same as “lot for lot” model, with one difference: for all items to which the model is applied goods on hand are not kept, and the process of ordering to cover the requirement starts only when the requirement is noticed.1） 会议的标准模式库存补货的一般假设。2）分配一个特定的产品范围，对备件的分类为基础的群体之一。表1介绍了如何选择杰出的每个类别的覆盖要求，适当的方法。该表包括股票补充模式描述为“命令”。它应该被解释为“为同一地段”的模式，但有一点不同：对所有该模型应用于手头货物项目不能兑现时，并下令要求采访过程开始的要求时，才发现是。E. Parameterization of the applied systemThe knowledge of general parameters characterizing individual spare parts is essential regardless of the accepted stock replenishment model. These parameters include:1) The service level.2) The replenishment lead time.3) The time variation of replenishment lead time.A very crucial parameter which characterizes each spare part is the accepted customer service level. The level depends, from one hand, on the strategy that the company adopted, but on the other hand on whether the customers (purchasers) accept it. Consequently, CVA analysis can be helpful in determining the customer service level.The suggested level of customer service understood as the probability of not meeting the demand in the replenishment lead time for particular categories created by assigning items according to CVA and ABC analyses is shown in Table 2.TABLE 2SUGGESTED VALUES OF CUSTOMER SERVICE LEVEL IN TERMS OF PROBABILITY FOR SPARE PARTS ASSIGNED TO PARTICULAR CATEGORIES ACCORDING TO CVA AND ABC ANALYSESThe other two general parameters which also determine the level of goods on hand are connected with the time of fulfilling the order for individual spare parts.另外两个一般参数也确定货物手头水平与履行个别备件订货时间有关。IV. THE EMPIRICAL VERIFICATION OF THE MODEL四。该示范实证验证The stages of implementing of the suggested model described in the previous chapters were translated into algorithms, which in turn bec