外文翻譯----等待隊(duì)列與模式

1、附件 附件外文翻譯 外文翻譯英文Waiting lines and simulationThe “miss manners” article pokes fun at one of life’s realities; having to wait in line.no boubt those waiting in line would all agree that the solution to the problem is obvio

2、us;simply add more servers or else do something to speed up service.although both edeas may be potential solutions,there are certain subleties that must be dealt with. For one thing, most service systems have the capacit

3、y to process more customers over the long run than they are called on to process. Hence,the problem of customers waiting is a short-term phenomenon. The other side of the the coin is that at certain times the servers are

4、 idle, waiting for customers. Thus by increasing the service capacity, the server idle time would increase even more. Consequently,in designing service systems,the designer must weiht the cost of providing a given level

5、of service capacity against the potential(implicit) cost of having customers wait for service. This planning and analysis of service capacity frequently lends itself to queuing theory,which is a mathematical approach to

6、the analysis of waiting lines.The foundation of modern queuing theory is based on studies about automatic dialing equipment made in early part of the twentieth century by Danish telephone engineer A.K.Erlang. Prior to Wo

7、rld War II,very few attempts were made to apply queuing theory to business problems. Since that time, queuing theory has been applied to a wide range of problems.The mathematics of queuing can be complex;for that reason,

8、the emphasis here will not be on the mathematics but the concepts that underlie the use of queuing in analyzing waiting-line problems. We shall rely on the use of formulas and tables for analysis.Waiting lines are common

9、ly found wherever customers arrive randomly for services. Some examples of waiting lines we encounter in our daily lives include the lines at supermarkdt checkouts,fast-food restaurants,aipport ticket counters,theaters,

10、post offices,and toll booths. In many situations, the “customers” are not people but orders waiting to be filled ,trucks waiting to be unloaded,jobs waiting to be processed,or equipment awiting repairs. Still other exa

11、mples include ships waiting to dock, planes waiting to land,hospital patients waiting for a nurse,and cars waiting at a stop sign.One reason that queuing analysis is important is that customers regard waiting as a non-Th

12、e costs of customer waiting include the salaries paid to employees while they wait for service(mechanics waiting for tools,the drivers of trucks waiting to unload),the cost of the space for waiting(size of doctor’s waiti

13、ng room,length of driveway at a car wash, fuel consumed by planes waiting to land),and any loss of business due to customers refusing to wait and possibly going elsewhere in the future.A practical difficulty frequently e

14、ncountered is pinning down the cost of customer waiting time, especially since major portions of that cost are not a part of accounting data. One approach often used is to treat waiting times or line lengths as a policy

15、variable: A manager simply specifies an acceptable level of waiting and directs that capacity be established to achieve that level.The traditional goal of queuing analysis is to balance the cost of providing a level of s

16、ervice capacity with the cost of customers waiting for service. Figure 1 illustrates this concept. Note that as capacity increases, its cost increases. For simplicity, the increase is shown as a linear relationship. Alth

17、ough a step function is often more appropriate ,use of a straight line does not significantly distort the picture. As capacity increases,the number of customers waiting and the time they wait tend to decrease, thereby de

18、creasing waiting costs. As is typical in trade-off relationships, total costs can be represented as a U-shaped curve. The goal of analysis is to identify a level of service capacity that will minimize total cost.( Unlike

19、 the situation in the inventory EOQ model,the minimum point on the total cost curve is not usually where the two cost lines intersect. )In situations where those waiting in line are external customers(as opposed to emplo

20、yees),the existence of waiting lines can reflect negatively on an organization’s quality image. Consequently, some organizations are focusing their attention on providing faster service—speeding up the rate at which serv

21、ice is delivered rather than merely increasing the number of servers. The effect of this is to shift the total cost curve downward if the cost of customer waiting decreases by more than the cost of the faster service.Cos

22、t 0 Optimum Service capacityCost of customers waitingTotal cost Cost of service capacityFigure1: The goal of queuing analysis is to minimize the sum of two costs: customer waiting costs and service capacity cost. System