Information Systems Analysis and Design CSC340 XVII System Design What is System Design The Outputs of System Design The Global System Architecture Classification of Applications State of the Market 2004 John Mylopoulos System Design 1 Information Systems Analysis and Design CSC340 Major Tasks of System Design Identify major hardware and software subsystems and components Identify usage control or data dependencies among subsystems Decide on a hardware and software platform for the new system Design the information system software database and user interfaces 2004 John Mylopoulos System Design 2 Information Systems Analysis and Design CSC340 Other Elements of System Design Not discussed in this course Plan control aspects of the application Test plans Code development standards Priorities for design trade offs Implementation requirements e g data conversion System Design 3 2004 John Mylopoulos Information Systems Analysis and Design CSC340 System Architecture System refers to both hardware and software The system architecture describes the collection of inter connected hardware nodes on which the software will eventually run A system architecture consists of Hardware nodes e g 486 2MB RAM 100MB disk OS DOS Windows The connectivity among nodes e g length 100ft type fiber optic product Novell 386 LAN PC3270 The location of users inputs and outputs Key concern Minimize Minimize data data communication communication 2004 John Mylopoulos System Design 4 Information Systems Analysis and Design CSC340 Example To each hardware node associate users actors and network interconnections 486 DOS Win 100MB disk 200ft Ethernet 100ft Twisted Novell 386 LAN 486 DOS Win pair PC3270 100MB disk Accounts Receivable OS 400 5 trm 5GB disk 100mi modem Accounts Payable 28800 PC3270 386 notepads DOS 80MB disk Business Administrator 1 500ft Twisted pair SNA IBM 3090 MVS 25 terminals 100ft Token ring Novell386 486 DB server 1mi fiber opt DOS 2GBdisk TCP IP 486 DOS Win 100MB disk Financial Managers VP Finance Purchasing Department 2004 John Mylopoulos System Design 5 Information Systems Analysis and Design CSC340 Distribution Issues How Are Data Processed Batch mode e g incoming outgoing surface mail purchase orders invoices cheques On line mode can save data entry time particularly if end user can do the input clearly the way of the future Remote batch data are input on line on remote machines then fed in batch to centralized database 2004 John Mylopoulos System Design 6 Information Systems Analysis and Design CSC340 New Technologies for I O and New Standards for Data Interchange Keyless data entry bar coding optical character recognition special keyboards Pen input several products in the market Electronic data interchange EDI data are transferred through telephone lines from one location to another e g credit card charging Image and Document Interchange like electronic data interchange e g law enforcement banking HTML XML SGML markup languages for documents SGML is a general markup languages for documents 2004 John Mylopoulos System Design 7 Information Systems Analysis and Design CSC340 Choosing a System Architecture Here is a series of issues that need to be addressed Establish batch and on line computer processes e g on site conference registration Determine process cycles i e when does each process need to run e g end of month end of project Establish processing locations identify user locations and numbers Distribute data to locations Distribute software subsystems to locations Assign technology what hardware software is going to run where 2004 John Mylopoulos System Design 8 Information Systems Analysis and Design CSC340 Classification of Applications Operational Support Span Type Decision Support Real Time browsing analysis E g video conferencing within group Group Dept E g regional inventory control E g regional marketing info system Enterprise E g enterprisewide cash mgt E g corporate E g enterprwide videodata conference warehouse InterEnterprise E g B2B Ecommerce E g E g DBs for communities of distributed multimedia interest over the internet System Design 9 2004 John Mylopoulos Information Systems Analysis and Design CSC340 State of the Market Span Type Operational Support Decision Support Real Time browsing analysis Group Dept PC Windows OLTP OO products COTS mainly SQL based Multimedia technology maturing Enterprise ERPs OLTP over private intranets ERPs Webbased products ERPs Webbased technologies InterEnterprise Ecommerce technologies Web based technologies Web based technologies OLTP On Line Transaction Processing ERPs Enterprise Resource Planning systems COTS Components Off The Shelf 2004 John Mylopoulos System Design 10 Information Systems Analysis and Design CSC340 Data Management Issues Identify amount and type of data persistence needed Is simple file I O sufficient Is a Database Management System DBMS required A DBMS is typically needed when Data is accessed at a fine level of detail Sophisticated indexing is required There is a need to port data across multiple platforms Data needs to be accessible from multiple platforms Isolate persistence persistence mechanisms mechanisms from from application application 2004 John Mylopoulos System Design 11
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