Information Systems Analysis and Design CSC340 Information Systems Analysis and Design CSC340 The Information System Lifecycle Again XVI System Design Survey project scope feasibility What is System Design The Outputs of System Design The Global System Architecture Classification of Applications State of the Market feasibility study Study current system problem statement initial requirements project request Select feasible solution System Design delivered system new system System Design 1 Information Systems Analysis and Design CSC340 2003 Jaelson Castro and John Mylopoulos 2003 Jaelson Castro and John Mylopoulos System Design 3 Information Systems Analysis and Design CSC340 Hardware networking and software platform for the new system A global system architecture which describes the hardware nodes and communication connections among them A software architecture for the new system showing the hierarchy of subsystems and their inter dependencies An allocation of subsystems and data to hardware nodes A detailed description of interactions between different elements of the design through sequence collaboration state and activity diagrams A database design consisting of a database schema for the data managed by the new system User interfaces for different groups of users 2003 Jaelson Castro and John Mylopoulos S W Construct new system System Design 2 CSC340 Not discussed in this course Plan control aspects of the application Produce test plans Specify code development standards Set priorities for design trade offs Identify implementation requirements e g data conversion 2003 Jaelson Castro and John Mylopoulos System Design 5 System Design 4 Information Systems Analysis and Design CSC340 Global System Architecture Outputs of the Design Phase design spec Deliver new system Other Elements of System Design Identify major subsystems and components Identify usage control or data dependencies among subsystems Decide on a hardware and software platform for the new system I e the hardware and network s on which it will run the operating system and other off the shelf software e g DBMSs it will use Allocate subsystems to hardware nodes for a possibly distributed system Decide on a data management strategy Choose a strategy and standards for human computer interfaces Select Acquire new S H W configuration Information Systems Analysis and Design Major Concerns of System Design detailed requirements Design new system Maintain improve system 2003 Jaelson Castro and John Mylopoulos Define end user reqs Describes the collection of inter connected hardware nodes on which the system will eventually run A global system architecture consists of Hardware nodes where components of the new system will run for each node select a hardware configuration and operating system platform that will run for example hardware platform 486 2MB RAM 100MB disk OS DOS Windows The connectivity among hardware nodes defined by length of connection type of connection product used for the connection for example length 100ft 100miles type twisted pair fiber optic ethernet product Novell 386 LAN PC3270 The location of users inputs and outputs for the new system Key concern Minimize data communication 2003 Jaelson Castro and John Mylopoulos System Design 6 Information Systems Analysis and Design CSC340 Information Systems Analysis and Design Example Distribution Issues To each hardware node associate users external entities and network interconnections 100ft Twisted pair PC3270 486 DOS Win 100MB disk 200ft Ethernet Novell 386 LAN 486 DOS Win 100MB disk Accounts Receivable Accounts Payable OS 400 5 ter 5GB disk 100mi modem 28800 PC3270 Business Administrator 1 500ft Twisted pair SNA IBM 3090 MVS 25 terminals 386 notepads DOS 80MB disk CSC340 100ft Token ring Novell386 486 DB server 1mi fiber opt DOS 2GBdisk TCP IP Batch mode process a batch of inputs outputs together sometimes most appropriate solution e g incoming mail purchase orders outgoing mail invoices cheques On line mode process inputs outputs as they become available can save data entry time particularly if end user can do the input clearly the way of the future because on line data entry can be done on PCs Remote batch data are input on line on several machines then fed in a batch mode to a centralized database 486 DOS Win 100MB disk Financial Managers VP Finance Purchasing Department 2003 Jaelson Castro and John Mylopoulos System Design 7 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 very appropriate for large volumes of I O Pen input several products in the market with mixed success rate for different types of data 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 but now whole documents including images are passed around e g law enforcement bank applications HTML XML SGML markup languages for documents SGML is a general markup languages for documents HTML is a special version used for WWW documents XML is something in between 2003 Jaelson Castro and John Mylopoulos System Design 9 Information Systems Analysis and Design CSC340 2003 Jaelson Castro and John Mylopoulos Information Systems Analysis and Design Type Operational Support Decision Support Choosing a System Architecture 2003 Jaelson Castro and John Mylopoulos browsing analysis E g regional marketing info system E g video conferencing within group Enterprise E g enterprisewide cash mgt E g corporate data warehouse E g enterprwide videoconference InterEnterprise E g B2B Ecommerce E g DBs for communities of interest E g distributed multimedia over the internet CSC340 State of the Market Type E g regional inventory control System Design 10 Information Systems Analysis and Design Real Time Group Dept CSC340 Here is a series of issues that need to be addressed Establish batch and on line computer processes key consideration data communication and response time 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 processor locations types and numbers storage devices and storage capacities connection protocols and traffic volumes Distribute data to locations simple solution all in one
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