数据库管理系统（DBMS）和管理信息系统（MIS）（二）

文章作者 100test 发表时间 2007:03:10 18:32:49
来源 100Test.Com百考试题网

The management information system（MIS）concept has been defined in dozens of ways．Since one organization’s model of an MIS is likely to differ from that of another，it’ s not surprising that their MIS definitions would also vary in scope and breadth．For our purposes，an MIS can be defined as a network of computer-based data processing procedures developed in an organization and integrated as necessary with manual and other procedures for the purpose of providing timely and effective information to support decision making and other necessary management functions．

　　Although MIS models differ，most of them recognize the concepts shown in Fig. 7-2．In addition to what might be termed the horizontal management structure shown in Fig．7-2（a），an organization is also divided vertically into different specialities and functions which require separate information flows（see Fig. 7-2（b））．Combining the horizontal managerial levels with the vertical specialities produces the complex organizational structure shown in Fig. 7-2（c）．Underlying this structure is a database consisting，ideally，of internally and externally produced data relating to past，present，and predicted furture events。

　　The formidable task of the MIS designer is to develop the information flow needed to support decision making（see Fig. 7-3）．Generally speaking，much of the information needed by managers who occupy different levels and who have different responsibilities is obtained from a collection of existing information systems（or subsystems）．These systems may be tied together very closely in an MIS．More often，however，they are more loosely coupled．

　　管理信息系统（MIS）的概念已经用数十种方式定义过。因为MIS的组织模型可能各不相同，所以MIS的定义随应用范围和广度而变化就不奇怪了。本文认为MIS系统可定义为基于计算机的数据处理过程的网络系统，它是一个机构为了支持决策及其他必需的管理功能提供及时有效的信息而开发的，并且可按需要把人工和其他过程结合在一起。

　　尽管MIS模型不同，但其中大多数都认可如图7-2所示的概念。除图7-2（a）中所示的横向管理结构如何命名之外，一个机构从纵向也可分成需要独立信息流的不同职能部门（见图7-2（b））。综合横同管理级和纵向特长产生了如图7-2（c）所示的复杂组织结构。这个结构的基础是数据库，该数据库理想的方式是由内部和外部产生的，与过去、现在及预见到的将来事件相关的数据组成。

　　MIS设计者的一个棘手的问题是开发支持决策所需的信息流（见图7-3）。一般而言，不同级别与不同职责的管理者所需的信息大多来自现有信息系统（或子系统）的汇集，这些系统在MIS中可紧密地结合在一起，但是，更经常的情况是松散耦合的。