英语翻译A management information system should efficiently perfo

英语翻译
A management information system should efficiently perform four functions:
Collect data Store data Update data Process data
The value of an MIS lies in its ability to accumulate data so that it can be manipulated or processed into information.Computer programs process data by summarizing,merging,selecting,and sorting it according to the needs of an MIS user.Once the computer has performed these functions,the information is ready for circulation to managers.
Collecting Data
Before an MIS can produce information,someone must feed it data.In determining whether data in an MIS,three questions have to be asked:
1.Is the data accurate?2.Is the data timely?3.is the data too expensive?
Inaccurate or obsolete date is useless.And some data that is both accurate and timely may simply not be worth the cost collection.Identifying this data requires a cost-benefit analysis.
Storing Data
Storing data simply means saving it for later use.Once collected,MIS data is entered into the computer for later processing into information.Computer systems may store data in two places:in the main memory,or on auxiliary storage devices,such as magnetic tapes,hard disks,or floppy disks.As noted earlier,the main memory holds programs and data that the computer is currently using.For permanent storage,uses can rely.on auxiliary storage devices like backup disks.
The anticipated use of the data determines the type of auxiliary storage device to use in storing it.Data that will rarely be accessed,read or written,is frequently stored on magnetic tape rather like the tape in an audio or videocassette.Magnetic tape is also used when data must be retrieved by sequential access.In other words,if a user wants to locate a particular file,the computer must read all the entries preceding the file before it can access the file.A typical 2,400-foot reel of magnetic tape can store up to 150 million characters.
A hard disk can store hundreds of millions of characters and you can randomly access them.Random access means that a computer can retrieve any piece of data from the source in the same amount of time as any other piece and that the time required to access the last record will be no greater than that required for the first.Thus,random access is the opposite of sequential access.For some years a floppy or flexible disk,with random-access capability,has been the most common type of auxiliary storage device.A floppy disk can hold up to 1.2 megabytes and is quite inexpensive.
Updating Data
Data would be of little value if it could not be updated and refined.Updates are of three types:adds,changes,and deletes.For example,a store’s MIS will include its inventory.The store will add to that inventory new classes of merchandise.It may also have to existing data.And,finally,the store may delete items dropped from stock.

一个管理信息系统应有效地履行四项职能：
收集数据的存储数据的更新数据处理数据
的价值,在于它的管理信息系统的能力,积累数据,以便它能够被操纵或加工成的信息.计算机程序处理数据的总结,合并,选择,和排序它根据需要的管理信息系统的用户.一旦计算机执行这些职能,准备的资料,分发给管理人员.
收集数据
在一个管理信息系统能够产生的信息,必须有人养活它的数据.在确定是否一个MIS系统中的数据,有三个问题要问：
1 .的数据准确吗?2 .及时的数据?3 .是数据太昂贵?
不准确或过时的日期是没有用的.和一些数据,是准确和及时的可能根本不值得收集的成本.确定这一数据需要进行成本效益分析.
存储数据
数据存储只是意味着保存供以后使用.一旦收集,管理信息系统的数据输入到计算机后加工成的信息.计算机系统可存储数据在两个地方：在主记忆体,或辅助存储设备,如磁带,硬盘或软盘.如前所述,主存储器拥有程序和数据的计算机正在使用.永久储存,使用可以依靠.辅助存储设备一样的备份磁盘.
预计使用的数据类型决定了辅助的存储设备使用的存储.数据,很少访问,阅读或书写,经常储存在磁带而不是像磁带中的音频或录像带.磁带也用于数据时必须检索顺序存取.换句话说,如果用户想要找到一个特定的文件,计算机必须阅读所有条目前面的文件,然后才可以访问该文件.一个典型的2400英尺一卷磁带可以存储多达150万字.
硬盘可以存储数百万字,你可以随机存取.随机存取意味着一台计算机可以检索任何一段数据从源在相同的时间内作为其他任何棋子,而且所需的时间,进入最后的记录将不会大于所需第一.因此,随机存取是相反的顺序存取.一些年来,灵活的软盘或光盘,并随机存取能力,一直是最常见的辅助存储设备.软盘可容纳1.2兆字节,是相当便宜.
更新数据
数据将没有什么价值,如果它不能得到更新和完善.更新的三种类型：增加,修改和删除.例如,一个商店的管理信息系统将包括其库存.这家商店将增加,库存的新类别的商品.它可能还需要现有的数据.最后,商店可删除项目从股票.