Introduction and literature review. Since Harris first published the basic EOQ model, many. Chapter 19 Inventory Theorysituations where the inventory level is under continuous review.
The EOQ model with planned shortages addresses this kind of situation by replac-. The discussion First, Section 2 presents a review of the literature. Cost Inventory Control Management Sales Ordering …11 Oct The proposed inventory model is the basic economic order quantity model with lead times. Literature Review Concluding Remark. Inventory; EOQ ; environmental awareness; carbon emission;. What is the efficacy of economic order quantity in a small…13 Nov One approach used increasingly by larger businesses is economic order quantity EOQ.
Reviews are not available for this item. Access critical reviews of computing literature. Researches classified EOQ problem to operations management and inventory theory. The result of the Review of Related Literature. A State of art on economic production quantity … Economic ordering quantity is a commonly accepted inventory management model.
This model is being used in planning the purchase raw materials, and suppliers, and in planning purchases for wholesalers and retailers who resell products. It is necessary to the inventory management that EOQ model is one of the most commonly approach. Use this model is relatively simple, however, according to Heizer and Render , p. Lead time is certainty and constant, therefore, when the stock down to zero, the stock could be added at a precise time.
Setup cost and holding or carrying cost are belong to variable costs. In fact, the EOQ is balancing two inventory management costs: Carrying costs include out-of-pocket costs such as storage, insurance, taxes and so on. Opportunity costs is related to the cost of investing capital in inventory rather than in other income-producing assets. Ordering costs include out-pf-pocket expenditures incurred every time an order is placed, such as handling, shipping, and so on. Carrying costs and ordering costs demonstrate different cost behaviors relative to the level of inventory maintained.
Carrying costs increase with the quantity of inventory maintained; ordering costs decrease with the quantity of inventory maintained. The more inventory kept on hand, the more storage, handling, and other such carrying costs are incurred.
The larger the amount of inventory, the fewer number of orders needed to replenish the inventory and the smaller the amount of ordering costs. As mentioned onwards, there are some assumptions will be dropped, like no quantity discounts, no shortages, no uncertainty in demand and lead time.
When the demand face seasonal changes, model can be changed to adapt to this situation. Martinich stated clearly: The important feature of EOQ model is that the function of total stocking cost is flat around the optimal order quantity. Estimating ordering cost per unit time and holding cost per unit time are very crucial, because they are not often very accurate.
Therefore, the value computed for EOQ cannot equal. As we mentioned above, it is difficult to decide accurate ordering costs and holding costs for inventory management. Thus, a robust model is very favorable and some errors do not cost us very much. This is because that the EOQ model is most convenient and it can accurately forecast demand, holding cost, and ordering cost is limited.
EOQ model is an approach of the fixed order point policy. According to Ellram et al. Throughout the ordering process, as long as the EOQ model was identified, a fixed quantity will be ordered every time. Another reorder policy is the fixed order interval method. Use this method, we may set time interval, maybe every week. Under this method, many projects are bought by the same supplier. As we all know, the most effective stock management approach is JIT production control system over the past 50 years.
The system is currently being used by many industries. For the purpose of JIT system, it intend to use minimum inventories of raw materials, process of production, and finished goods to achieve high output. Theoretically, if an item is sold, the market will pull a substitute in the system. Then this upstream station pulls to further upstream and back to release of raw materials. To make this pull process more smoothly, JIT need high quality in every procedure, strong supplier relationships, and a very clearly demand for the final product.
In JIT production system, Black et al. There are many approaches to use demand-pull feature, but the most common method is Kanban system which is the Japanese term for a visual record or card.
Under Kanban system, use a kanban card to operate to authorized another operation to produce a given part of the special quantity. The assembly department triggers productions of the 10 metal pipes it needs to make the 10 mufflers by sending a kanban card to the machining department, which then begins producing the pipes.
When production is completed, the machining department attaches the kanban card to the box containing the mental pipes and ships the package downstream to the assembly department, which starts the cycle over again when it receives the next customer order. Each unit including the setup time and manufacturing lead time are minimized. When a product is prepare to begin in production line, then turned into finished products, the process of the elapse of the time is known as manufacturing lead time.
Production of demand normally produced relatively small quantities, however, as long as setup times are small, it is cost-effective to produce product in small quantities. If parts have defective and insufficient, the production line will cease operation. Each staff should attach great importance to reducing the occurrence of such problems like defective material parts. Conversely, under the traditional inventory management system, workers can ignore defective parts and continue to work because the inventory parts and work in process are huge.
All the staff have become quality control inspection personnel, meanwhile, if products and materials are found to be not meeting quality standard, the production line should suspend operation. As long as this situation happened, it must be resolved as soon as possible. It means that workers have not impetus to ignore the fault in the early of production process stage, they had to stop their work process. The fundamental difference between JIT method and other traditional methods is the treatment of the costs.
According to Hirsch et al. After these amounts are transferred into a work-in process account, they will be put into operation as raw materials. The value of material is diverted to finished product inventory account because the product has been completed. In JIT purchasing, suppliers use the replacement principle of Kanban by using small, standard-size containers and make several shipments daily to each customer.
JIT not only reduces in-process inventories by using Kanban, but also raw materials inventories are reduced by applying the same principles to suppliers as well. According to Frazier and Gaither Supplier development and supplier relations undergo fundamental changes. The nature of the relationships between customers and suppliers shifts from being adversarial to being cooperative.
The Japanese call these relationships subcontractor networks and refer to suppliers as co-producers. Purchasing departments develop long-term relationships with suppliers. The result is long-term supply contracts with a few suppliers rather than short-term supply contracts with many suppliers.
Although price is very important, delivery schedules, product quality, and mutual trust and cooperation become the primary basis of supplier selection. Suppliers are encouraged to extend JIT approach to their own suppliers. This causes lead times to be shorter and more reliable. Because suppliers are encouraged to produce and supply parts at a steady rate that matches the use rate of the buying firm, company-owned hauling equipment tends to be preferred.
Parts are delivered in small, standard-size containers with a minimum of paperwork and in exact quantities. Delivered material is of near-perfect quality. Because suppliers have a long-term relationship with the buying firms and because parts are delivered in small lot sizes, the quality of purchased materials tends to be higher. In the practice of business arena, although EOQ model enable to generate many good results, many limitations of EOQ model is combined with its own assumptions.
In practice, demand is assumed to be constant, but in many cases demand is shifty. The unit cost is assumed constant, in practice, however, normally if the purchase of large quantities, it will gain quantities discounts.
The material in the lot is assumed to arrive all at once, but in some cases material will be placed in inventory continuously as it is produced. This case is also treated in the supplement. A single product is assumed, however, sometimes several projects were purchased through a single provider. Meanwhile they are being shipped at one time. Suppose the setup cost is static, as a matter of fact, it is always decreased.
These assumptions have been pointed out to illustrate the limitation of the basic EOQ model, nevertheless it is useful approximation in practice. In addition, the total-cost curve is rather flat in the region of the minimum. Therefore the EOQ can be adjusted somewhat to conform to reality without greatly affecting the costs. The EOQ formula can also offer insight into economic behavior of inventories. For example, traditional turnover arguments suggest that inventory should increase directly with sales if a constant turnover ratio is desired.
Since turnover is the ratio of sales to inventory, a doubling of sales will allow a doubling of inventory if the turnover rate is held constant. But the EOQ formula suggests that inventory should increase only with the square root of sales. This indicates that it is net economical to maintain a constant turnover ratio as sales increase; a higher turnover is indeed justified.
It is important for financial manager that fully understand limitations and assumptions of the EOQ model will offer a strong base of making stock management decision. Obviously, through the above discussion, some assumptions of EOQ model are impractical. In order to make this model more useful, it is necessary to extension for EOQ model. Besley and Brigham , pp. The amount of safety stock a company holds generally increase with a the uncertainty of demand forecasts, b the costs in term of lost sales and lost goodwill that result from stockouts, and c the chances that delay will occur in receiving shipments.
The amounts of safety stock decreases as the cost of carrying this additional inventory increase. Moreover, a company should consider when determining appropriate inventory level is whether its supplier provides discounts to purchase large quantities.
The Economic Order Quantity (EOQ) model is a pure economic model in classical.. however, a literature review conducted reveals that there are no studies A Proposed Approach to Extend the Economic Order Quantity quantity (EOQ) model using discrete event simulation.
Economic Order Quantity Literature Review Business Decision Science INTRODUCTION In business, managers are faced with “how much” or “how many” of something to make or buy in order to satisfy consumer demand . Some businesses will order every month while others might order a 89%(9).
*An essay is a piece of writing usually written from an author's personal point of view that analyses and evaluates an issue or a topic. Writing an essay means to express your academic opinion on a particular matter. Possible types include: descriptive essay, narrative essay, compare and contrast essay, persuasive essay, argumentative essay etc. Literature Review Economic Order Quantity History “Origin of the conomic Order Quantity formula; transcription or transformation?” Bill Roach explains how the origin of the Economic Order Quantity began in his article, “rigin of the conomic rder uantity formula; .
the basic economic order quantity model In , F. W. Harris developed an EOQ model which has been applied widely. This model is being used in planning the purchase raw materials, and suppliers, and in planning purchases for wholesalers and retailers who resell products. Literature review on economic order quantity. 11 settembre / in Senza categoria / da. After watching this video essay i might watch mad men. nuclear power friend or foe essay. internship experience report essays. a view from the bridge law and justice essay. essaye conjugation of estar.