دانلود مقاله ISI انگلیسی شماره 23373
عنوان فارسی مقاله

مدل تجزیه و تحلیل هزینه برای تجهیزات سنگین

کد مقاله سال انتشار مقاله انگلیسی ترجمه فارسی تعداد کلمات
23373 2009 13 صفحه PDF سفارش دهید محاسبه نشده
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عنوان انگلیسی
A cost analysis model for heavy equipment
منبع

Publisher : Elsevier - Science Direct (الزویر - ساینس دایرکت)

Journal : Computers & Industrial Engineering, Volume 56, Issue 4, May 2009, Pages 1276–1288

کلمات کلیدی
هزینه سیستم چرخه عمر - هزینه مسئولیت - هزینه محصول پس از ساخت () - هزینه مالکیت - هزینه های عملیاتی()
پیش نمایش مقاله
پیش نمایش مقاله  مدل تجزیه و تحلیل هزینه برای تجهیزات سنگین

چکیده انگلیسی

Total cost is one of the most important factors for a heavy equipment product purchase decision. However, the different cost views and perspectives of performance expectations between the different involved stakeholders may cause customer relation problems between the manufacturers and customers. Beginning with the conventional manufacturers’ cost view, this paper presents the necessity and importance of expanding the heavy equipment manufacturers’ cost scope to include the post-manufacturing customer stage of their products. Then, this paper narrates a general mathematics Post-Manufacturing Product Cost (PMPC) model to analyze the total costs of heavy equipment in its utilization stage. A major emphasis of the PMPC model is placed on the strategy of improving the manufacturers product cost management and the strategy of customers purchasing decisions cost management and their interdependencies as related to their specific different perspectives on the product utilization patterns.

مقدمه انگلیسی

In the last century, new product development in the manufacturing environment has changed significantly to meet the challenge of global competition. To survive internationally, manufacturing firms must strategically examine customer needs and values in all their served market segments. Increasing complexity and costs of new products place an increased importance on a system life-cycle cost analysis by the vendors and customers. Furthermore, this life-cycle cost view is of particular importance for revenue generator products. For instance, Hitachi Construction Truck Manufacturing, Ltd. is a multi-international manufacturer for off-highway, rigid dump trucks. Its products consist of 30 to over 300 ton rigid haulers with typical life spans of approximately 10 years. The initial cost of rigid haulers can be over one million dollars and corresponding operating costs approximately three to four times of the initial cost. Under these circumstances, a proper cost-evaluating model becomes extremely important. The traditional cost analysis models can be classified into three categories: manufacturer-oriented cost analysis models, end-user-oriented cost analysis models, and life-cycle cost models. The typical manufacturer-oriented cost analysis models include productive hour rate costing, process costing, activity-based costing, and precision engineered costing system. Ostwald’s Productive Hour Rate Costing Model calculates the productive hourly rate by adding the machine hourly rate and the direct labor hourly rate (Sims, 1995). Woods’s Process Costing Model assigns costs to process by accounting for the degree to which the processes cause costs to be incurred (Clark & Lorenzoni, 1978). Activity-Based Costing (ABC) solves the cost accounting precision problem by assigning “cost drivers” to the various sources or elements of manufacturing expense. Sims’s Precision Engineered Costing System is a cost method for both piece part and continuous process manufacturing operations. Sims’s System focuses on the cost-finding impact of capital intensive and high tech operations. Manufacturer-oriented cost analysis models are deployed by manufacturers to analyze product manufacturing and warranty cost. The major problem with those models is that they can only be applied to manufacturing cost analysis. In other words, they are not total cost analysis models. Therefore, those models can not provide the total cost data to meet customer needs. The typical end-user-oriented cost analysis models include Benefit-Cost Analysis (BCA) and Total Cost Analysis (TCA). Benefit-cost analysis, which is also known as Cost-benefit analysis, was first demonstrated by Benjamin Franklin in one of his letters from the 1770s. Since its conception, Cost-benefit analysis has been widely deployed in the fields of health and community services, defense and R&D, natural resources, transport, and investment problems (Berliner et al., 1988 and Gramlich, 1981). BCA includes two topics: the formulation of alternatives; and the enumeration, quantification, and (when possible) valuation of the relevant costs and benefits of each decision algorithm and preference function (Turvey, 1971). The Total Cost Analysis (TCA) approach suggested by DeCorla-Souza, Everett, Gardner, and Culp (1997) is an alternative to Benefit-Cost Analysis (BCA) for evaluating transportation alternatives. In the TCA approach, benefits involving “cost savings” are automatically considered on the “cost” side of the equation and not the “benefits” side. In BCA, most or all monetized benefits are really cost savings. The main problem with end-user-oriented models is that the product most likely will play a static role in the analysis process. End-user-oriented models, which are deployed by end-users and not manufacturers, attempt to make general criteria for computing operating cost. Regardless of the performance variation among the same type of products from different manufacturers, end-user-oriented models only consider the variation of the product’s quantity and functionality. Once the quantity and functionality are determined, the operating cost of the equipment is determined. The best interest of those models is to pick an optimal solution from a group of candidates on the method/path level. In other words, they do not really analyze the cost of different entities performing the same task. For instance, the TCA model for transportation cost analysis classifies the transportation tools into three different categories: private vehicle, public bus, and rail. Upon selecting the “private vehicle” category, the TCA model will not help in picking a kind of “private vehicle”. The result of those models helps people make high level decisions, but it does not helps manufacturers or customers when promoting the product or making the purchase decision. Fig. 1 presents a typical product/system life-cycle economic model from the manufacturer perspective as described by Chen and Keys (2003). It demonstrates the costs incurred to the manufacturer from marketing’s conceptual development through prototype design, development into production, and field costs. Keys (1991) identifies field costs as including manufacturer covered post-manufacturing cost items, such as warrantee optimization, associated dealer/customer allowances, and customer service. More details on these costing can also be found in Keys, 1990, Locascio, 2000, Sheldon et al., 1991, Keys et al., 1987 and Menezes, 1990. Full-size image (59 K) Fig. 1. System production/technology economic life cycles. Figure options In general, the utilization costs of heavy equipment contain two parts: ownership costs and operating costs. The operating costs are normally much bigger than the ownership costs. There is now a clear understanding between manufacturers and customers. One of the fundamental cost problems so-called “lack of total cost visibility” as reported by Blanchard (2003) in Fig. 2 has been well recognized after introducing the principle of the system life-cycle cost. However, when investigating those visible and invisible costs in detail, manufacturers and customers start to show their significantly different interests, perspectives and concerns. These differences are the issues of the typical life-cycle cost model. Full-size image (28 K) Fig. 2. Total cost visibility. Figure options First, different concerns will be presented regarding costs. While all costs are integrated, the typical system life-cycle cost view does not clearly distinguish the different cost “partner” responsibilities, (i.e., the different detailed cost concerns). Traditionally, a major concern of manufacturers is all about the Product Manufacturing Cost (PMC). On the other hand, customers could care less about the PMC. Their focus is on the costs to own/lease the machine and keep it running (i.e., the total product utilization cost or the Post-Manufacturing Product Cost (PMPC) as reported by Chen (2002)). Fig. 3 depicts PMC and PMPC cost curves based on the system life-cycle cost view. Neither of these two cost concerns are completed because PMC and PMPC are interrelated. In order to create a long-term relationship with its customers, a heavy equipment manufacturer has to realize the trade-off between PMC and PMPC. Hence, the cost interests of a manufacturer should include both PMC and PMPC. Manufacturers can reduce PMC by using less expensive components or materials without considering the possibility of increasing the PMPC on the customer side. Full-size image (41 K) Fig. 3. PMC and PMPC curves. Figure options Second, differences in cost definitions will be presented. In a mining job site, cost data is collected on a regular basis so that the mine managers have a clear idea about the overall costs on the fleet. However, problems and disagreements will come out regarding how to properly allocate and analyze those costs. The collected cost data presents what is really happening in the field. However, this does not necessarily indicate the optical performance for the machine. Furthermore, not all machine costs are ultimately related to a manufacturers’ responsibilities. For example, manufacturers are not responsible for the costs of delay in repairs due to lack of required parts. Therefore, it is in the manufacturers’ best interests to separate the true machine cost factors away from the noise cost factors. In other words, manufacturers need to generate their cost models to identify the truly best economical performance of their machine by implementing a better understanding and a better technical knowledge of their products. While the ownership costs are more explicit in general, operating costs generally can be much more confusing and cause disagreements between manufacturers and customers. Finally, the best method for evaluating or comparing costs will be presented. There are three basic cost measurement methods: absolute costs ($), cost/time unit ($/h), and cost/productivity unit ($/ton). All three methods present different economic aspects of a machine. Absolute costs can be used to determine the overall investment. Cost/time unit can be used to determine the required budget for each year. However, when we are doing costs comparison between different products, cost/productivity unit ($/ton) is the only fair method. Furthermore, since heavy equipment is a profit-making machine, the ultimate goal for heavy equipment customers is maximizing the high gain–loss ratio. Therefore, the cost/productivity unit is the most common method to show a machine’s economic performance. In today’s business world, most people realize the importance of equipment operating costs impact their businesses (Waeyenhergh & Pintelon, 2004). This paper will first present a general cost structure for heavy equipment. Then, it narrates a general mathematics Post-Manufacturing Product Cost (PMPC) model to analyze the total costs of heavy equipment in its utilization stage. The concept presented in this paper is that manufacturers should extend their cost views to include their product utilization phases (i.e., having an integrated cost view). In addition, the cost model proposed in this paper intends to provide heavy equipment manufacturers a way to present their future machine total utilization costs to their potential customers.

نتیجه گیری انگلیسی

This paper presents an approach to define the total cost structure and an analysis method for using heavy equipment in general. The PMPC model is not an alternative solution for the LLC model because they are aiming on different subjects. From the high level cost view, LLC and PMPC have different research scopes. LLC includes all the costs for a product from the very beginning to the very end. On the other hand, PMPC focuses on the product’s costs in its utilization stage with the cost responsibilities clearly defined. Therefore, PMPC can establish a set of costs to present the true economic performance of the product accurately. By defining the cost responsibilities, it comprises a serious difference between PMPC and LLC. With the different cost responsibilities defined, some new elements are not being accounted. For example, the profit for the manufacturer is never a cost item in LLC. However, it is a cost for the end-user in PMPC by including itself into the purchase price. Moreover, some elements that are either hidden or not considered as cost in LLC, which includes OSLR and unused capacity cost, become very important in the PMPC. For instance, OSLR is the potential economic performance losses and not the actual cost. However,, it must be included if we want to compare the products’ economic performance on an “apple-to-apple” basis. Although PMPC is used to analyze the utilization costs, it suggests that the manufacturers should deploy the PMPC as a part of their manufacturing and marketing strategy in order to make their products more competitive. By implementing the concept, the heavy equipment manufacturers can create their own detailed cost models for their products. Such a model should be verified by the specific manufacturer’s historic data and real feedback from the field. For example, as described above, the predication of fuel consumption of a hauler is dependent on the simulation of a use-case study. Therefore, the simulation method has to be accurate in order to get precise results of fuel consumption. In Hitachi Construction Machinery organization, there is a software called CONSULT to perform these job studies. With the verification from the field tests, CONSULT’s results are in the satisfied tolerance range. There are two ultimate goals of the total cost analysis. One is to indicate the complete economic performance of a product. The other is to find solutions to reduce the total cost at the product design and development stages and not only effective manufacturing costs (Barton, Love, & Taylor, 2001). While the first goal is well recognized by the sales and marketing departments of companies, the second goal still needs to be emphasized through all departments in heavy equipment manufacturing. In fact, decisions made early in the design/development cycle (maybe only 20%) can “freeze” (effect) 75–80% of the total life-cycle costs as illustrated in Fig. 7. Details can be found in Goel and Singh, 1999, Woodward, 1997, Keys, 1997 and Blanchard and Fabrycky, 2000. Full-size image (31 K) Fig. 7. Commitment, system-specific knowledge, and cost. Figure options To summarize, the PMPC model proposed in this paper can be used by manufacturers to analyze the costs of the current products. Additionally, it can be used to predicate the costs of products when they are still in the design and development stages. For example, once the proper PMPC model is in place, the design engineer will be able to do “What-If” cost analysis on a component by component basis. By considering its part cost (PMC) and future operating and maintenance costs (PMPC), the design engineer will be able to make the most cost-effective decision. For their best interest, manufacturers should be responsible to provide the estimation of the total machines’ costs to potential customers. In order to accomplish this task, a successful manufacturer should distinguish its products from others and help equipment buyers to lower their future operating costs (i.e., scheduling properly, optimizing maintenance events, etc.). Based on the same philosophy, the concept of this paper can be transferred into a variety of operating cost-related products, such as super electric systems, passenger cars, and telecomm-equipment.

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