30 Apr Management Information Systems 12. Components of Enterprise Information Systems by Asst. Prof. Wichai Bunchua

30 Apr Components of Enterprise Information Systems Hardware Programs Data Procedures People

30 Apr Hardware LANs Teleprocessing Systems Internets Backbone Networks

30 Apr LAN Characteristics Multiple microcomputers connected together One or more file, database, or other servers Bus ans ring topologies are common Computers within a mile or two of each other Generally fewer than 50 computers

30 Apr Teleprocessing Systems Characteristics Processing performed by cenralized computer Users access applications via dumb terminals or micros emulating dumb terminals

30 Apr Basic Components End-user hardware Communication media WANs and MANs Polling Multiplexing Processing hardware

30 Apr Communication Line Classifications Line speed Voice-grade ( bits per second) Wideband (500,000 bits per second or more) Line mode Analog Digital Line type Full-duplex Half-duplex Simplex

30 Apr Internets Charateristics Multiple LANs interconnected Requires Bridge Gateway Router

30 Apr Backbone Networks A large central network to which all the computers in an enterprise are connected It provides the infrastructure for enterprise telecommunications Communications backbones support at least three functions between users File transfer among computers Terminal emulation

30 Apr Backbone Networks Characteristics Network supports communications among computers of any type Hundreds or thousands of computers and terminals possible Wide geographic distribution possible via WAN

30 Apr Programs System programs Teleprocessing communications control Network communication control Horizontal Market Application programs Vertical Market Application programs Cuustom-developed Application programs

30 Apr Data Departmental data independencies Distributed database system International data communications

30 Apr Procedures The need for controls EDP controls Management controls Organization controls Data center resource controls I/P/O controls

30 Apr The Need for Controls Fictitious sales Illegal funds transfer Theft of equipment

30 Apr Types of Computer Crime Manipulating computer input Changing computer programs Stealing data Stealing computer time Stealing computer programs

30 Apr Categories of EDP Controls Management Organizational Data center resource I/P/O

30 Apr Types of Management Controls Attend to MIS applications Manage MIS activity Follow up on problems Take control procedures seriously

30 Apr Data Center Resource Control Control access to data center Locate data center in protected environment Pland and document operating procedures Protect libraries of program Plan and execute backup procedures Plan and practice recovery procedures Protect data center from natural hazards Protect international data center

30 Apr I/P/O Controls Input Documentation of authorized input format Separation of duties and authorities Verificaion of control totals On-line system input controls

30 Apr I/P/O Controls (cont.) Processing Documented operating procedures Reviews of processing logs Adequate program testing Output Documented output procedures Control over disposition of output Users trained to examine output

30 Apr People’s Roles Four different roles Use Development Operations Management

30 Apr The MIS Department Data processing Development -- System analysts, programmers Operation -- Operators, data-entry System support --System programmers Data administration Data administrator (DA) Database administrator (DBA) End-user support