1、中文 2637 字 外文翻译 Just-In-Time Inventory Management Strategy & Lean Manufacturing Material Source: Academy of Management Review Author: Steven White Overview of Just-in-Time Inventory Management Just-in-time is a movement and idea that has gained wide acceptance in the business community over the past
2、decade. As companies became more and more competitive and the pressures from Japans continuous improvement culture, other firms were forced to find innovative ways to cut costs and compete. The idea behind JIT, or lean manufacturing, is to have the supplies a firm needs at the exact moment that they
3、 are needed. In order to accomplish this goal a firm must constantly be seeking ways to reduce waste and enhance value. A recent survey of senior manufacturing executives showed that 71% used some form of JIT in their processes (Pragman). This simple statistic illustrates that JIT is here to stay an
4、d also that firms must constantly be searching for ways to cut costs and achieve an advantage. JIT is one way to achieve that end result. In order to understand how JIT works a common vocabulary needs to be established from which to further discuss the topic and gain insight into why so many firms h
5、ave adopted it. As previously stated, one of the key components of JIT is to reduce waste and add value. There are several activities that a company must monitor as targets for reducing waste. Among these are, excessive waste times, inflated inventories, unneeded people or material movement, unneces
6、sary processing steps, numerous variabilities throughout a firms activities and any other non-value adding activity. A key example of this is a new plant that Caterpillar is bringing on-line in the near future. By reducing the number of times a bucket had to be repositioned while it was being welded
7、, Caterpillar was able to reduce the amount of time the bucket spent in the welding line, reduce labor costs by limiting idle time at the welding station and increase the efficiency of the entire manufacturing process. The layout and inventories that are part of a JIT strategy may seem the most logi
8、cal steps to reduce waste and increase value. By simply redeveloping the layout of certain facilities a firm can reduce the time it takes for supplies to get to the next step in process and cut costs associated with that movement. One way to do this is to have work-in-progress close to the next stat
9、ion in the manufacturing chain. Couple this with lowering inventories and a powerful combination is formed to reduce costs. In lowering inventories a firm can reap numerous benefits； batch sizes, set-up times and safety stock are all reduced, ergo costs are trimmed and value is added. But in order t
10、o achieve these things a firm must be willing to accept the problems that these actions can either uncover or create. Dell Computers participates in both of these activities and they are now the industry leader. Dell has warehouse space at their manufacturing facilities in which suppliers keep parts
11、 directly on-site which is the quintessential JIT layout. In addition, Dell is constantly working to achieve JIT inventories of only four days and in doing so are constantly uncovering and solving supply chain problems. Going hand-in-hand with maintaining Just In Time inventory levels is JIT schedul
12、ing. By working to reduce inventory to the lowest possible working levels, a firm must constantly be adjusting its schedule of ordering and delivering. In doing so, communication both up and down the supply chain is critical. Frequent orders are placed for supplies and small production runs are cons
13、tantly being initiated. In order to achieve this breakneck pace of order/production schedule, a firm must constantly be making small changes to orders/production and recognize that kanbans are of incredible importance. Possibly the single piece of JIT that has the most relevance to a study of supply
14、 chain management is the partnerships that are essential to making JIT truly work. A firm cannot implement a JIT system by itself； it must have the complete cooperation of its entire supply chain.The sheer amount of information that is needed for a JIT system to operate well demands partnerships to
15、be formed and nurtured, almost to the point at which an entire supply chain operates as one firm. Examples of these kinds of partnerships are everywhere in todays business world. XYZ-Company allows its key suppliers to work directly at their manufacturing sites and place orders as needed for the par
16、ts that that supplier supplies. Other concepts of Just In Time also need to be introduced in order to have a discussion about what truly makes Just In Time a worthy endeavor. By the 1980s the Japanese had achieved manufacturing greatness by practicing continuous improvement, in that a firm is consta
17、ntly working to improve in every facet of its business functions. To do this a firm must always increase quality, look for innovative ways to solve problems and increase focus on the quality of its suppliers. All of these are cornerstones of a modern JIT system. Lastly, getting the workforce to buy
18、into a JIT lean manufacturing system is important because without the dedication of the workforce, any endeavor is sure to fail. There are several ways to achieve workforce commitment. A simple way is to cross train the workforce members outside of their normal business function and help increase an
19、 employees problem solving ability. In doing so a firm is empowering its workforce to think about their function in a new way while looking for ways to improve and giving them an overall view of the entire firm, not just their single job. When this is coupled with the support of management, an incre
20、ase in resources to solve problems, and an increase in employee roles and responsibility, a workforce will feel empowered and work to make Just In Time a success for the business. Strengths of JIT There is a lot of strength in incorporating JIT lean manufacturing in a company. JIT makes production o
21、perations more efficient, cost effective and customer responsive. JIT allows manufacturers to purchase and receive components just before theyre needed on the assembly line, thus relieving manufacturers of the cost and burden of housing and managing idle parts. In that respect, company spokesman for
22、 Dell Figueroa, says With our pull-to-order system, weve been able to eliminate warehouses in our factories and have improved factory output by double by adding production lines where warehouses used to be. The benefit of carrying smaller amounts of inbound, in-process, and finished goods inventory
23、exists regardless of the firms operating context (size, production technology, etc.). Just In Time appeals to many companies because it helps prevent manufacturers from being stuck with inventory that may become obsolete. JIT was initially developed and justified based on cost reduction and quality
24、improvement dimensions. Now, companies view JIT as providing an approach to achieving excellence in the elimination of waste, as well as making the company more responsive to short-term customer demand patterns. JIT manufacturing can be a real money-saver for a company. Companies are not only more r
25、esponsive to their customers, but they also have less capital tied up in raw materials and finished goods inventory, allowing companies to optimize their transportation and logistics operations (UPS, 2003). Overall, JIT manufacturing results in lower total system costs and improved product quality.
26、With JIT, some plants have reduced inventory more than fifty-percent and lead time more than eighty-percent. JIT is lowering costs and inventory, reducing waste, and raising the quality of products. Weaknesses of JIT Just as JIT has many strong points, there are weaknesses as well. In just-in-time,
27、everything is very interdependent. Everyone relies on everybody else (Greenberg, 2002). Because of this strong interdependence with JIT, a weakness in the supply chain caused by a JIT weakness can be very costly to all linked in the chain. JIT processes can be risky to certain businesses and vulnera
28、ble to the supply chain in situations such as labor strikes, interrupted supply lines, market demand fluctuations, stock outs, lack of communication upstream and downstream in the supply chain and unforeseen production interruptions. Labor strikes, stock outs, and port lockouts can quickly disrupt a
29、n entire supply chain while JIT processes are in place. Adhering to the just-in-time concept can be expensive in times of emergency such as at ports (Greenburg, 2002). When a ship arriving from Asia full of supplies cannot make it to shore, the company using JIT generally has very little inventory t
30、o compensate for the emergency. This lack of inventory is exactly what makes JIT so great to companies in reducing costs, yet making it risky as well by in some cases not having enough buffer inventories to react and keep the supply chain moving. Every year markets experience seasonal demand fluctua
31、tions as well as fluctuations due to demand from disasters or other unforeseen events. Just-in-time delivery leaves retailers and manufacturers with little inventory as the holiday season approaches (Greenberg, 2002). Relying solely on JIT systems would leave supply chains in shock due to the overwh
32、elming seasonal market demand at different times of the year for seasonal products. Not all products should be produced with JIT systems in place. Custom made items will not work well with JIT as JIT systems respond best to mass produced and highly automated production items. Weaknesses in JIT syste
33、ms are very important to recognize. From Cisco routers to Dell computers to the Gaps leather pants, companies have found their just-in-time manufacturing systems have let them down (Johnson, 2001). Companies must strongly evaluate the pros and cons of implementing JIT systems. The effects and risk t
34、o their supply chain must also be heavily considered. Although JIT has its weaknesses, in most cases, the benefits outweigh the risks to the JIT enabled company. Planning for and recognizing when things may go wrong with the JIT system are vital for the success of JIT implementation across all areas of supply chains.
