SYSTEMS ANALYSIS AND DESIGN METHODS 6 th Edition

Скачать презентацию SYSTEMS ANALYSIS AND DESIGN METHODS 6 th Edition

610d1b99f24f1c59dfa54147a9307390.ppt

Количество слайдов: 29

SYSTEMS ANALYSIS AND DESIGN METHODS 6 th Edition Whitten Bentley Dittman System Design and System Design Approaches System design (Also called physical design) – Systems design emphasizes the technical or implementation concerns of the system. – Where systems analysis emphasizes the business problem System Design Approaches (covered already) – Read following slides to refresh your memory. . – Model-Driven • • Modern structured design Information engineering Prototyping Object-oriented – RAD and JAD Irwin/Mc. Graw-Hill 2 Copyright © 2004 The Mc. Graw-Hill Companies. All Rights reserved

SYSTEMS ANALYSIS AND DESIGN METHODS 6 th Edition Whitten Bentley Dittman System Design Tasks For In-House Development (Build) • Design the Application Architecture – Defines the technologies to be used by (and used to build) one, more, or all information systems. – Revise models as physical models (e. g. Physical Data Flow Diagram) • Design the System Databases (see ERD example) – Database schema – Optimized for implementation DBMS • Design the System Interface – Input, output, and dialogue specifications – Prototypes • Package Design Specifications – Specifications to guide programmers • Update Project Plan Irwin/Mc. Graw-Hill 3 Copyright © 2004 The Mc. Graw-Hill Companies. All Rights reserved

SYSTEMS ANALYSIS AND DESIGN METHODS 6 th Edition Whitten Bentley Dittman System Design Tasks For Integrating Commercial SW (Buy) • Research technical criteria and options • Solicit proposals (or quotes) from vendors – Will vendors be able to provide service continuously? (survive) – Quality? (different than buy a group automobiles for an organization) • Validate vendor claims and performance • Evaluate and rank vendor proposals • Award (or let) contract and debrief vendors Irwin/Mc. Graw-Hill 4 Copyright © 2004 The Mc. Graw-Hill Companies. All Rights reserved

SYSTEMS ANALYSIS AND DESIGN METHODS 6 th Edition Whitten Bentley Dittman Context Of System Design For “Buy” Solutions To Projects Irwin/Mc. Graw-Hill 5 Copyright © 2004 The Mc. Graw-Hill Companies. All Rights reserved

SYSTEMS ANALYSIS AND DESIGN METHODS 6 th Edition Whitten Bentley Dittman C H A P T E R 13 Irwin/Mc. Graw-Hill 6 APPLICATION ARCHITECTURE AND MODELING Copyright © 2004 The Mc. Graw-Hill Companies. All Rights reserved

SYSTEMS ANALYSIS AND DESIGN METHODS 6 th Edition Whitten Bentley Dittman Distributed vs. Centralized Systems Distributed system – a system in which components are distributed across multiple locations and computer networks. Centralized systems – a system in which all components are hosted by a central, multi-user computer. • Cost – productivity • Security • Strategic plan – Empowerment of each Dept. or Division Irwin/Mc. Graw-Hill 7 Copyright © 2004 The Mc. Graw-Hill Companies. All Rights reserved

SYSTEMS ANALYSIS AND DESIGN METHODS 6 th Edition Whitten Bentley Dittman Why the Trend Toward Distributed Systems? • Modern businesses are already decentralized (distributed). • Distributed computing moves information and services closer to the customers and users who need them. • Distributed computing consolidates the power of personal computers across the enterprise. • Distributed computing solutions are in general more user-friendly because they use the PC as the user interface processor. • Personal computers and network servers are less expensive than mainframe computers – Though total cost of ownership is at least as expensive Irwin/Mc. Graw-Hill 8 Copyright © 2004 The Mc. Graw-Hill Companies. All Rights reserved

SYSTEMS ANALYSIS AND DESIGN METHODS 6 th Edition Whitten Bentley Dittman C H A P T E R 15 Irwin/Mc. Graw-Hill 9 OUTPUT DESIGN AND PROTOTYPING Copyright © 2004 The Mc. Graw-Hill Companies. All Rights reserved

SYSTEMS ANALYSIS AND DESIGN METHODS 6 th Edition Whitten Bentley Dittman Classification of Output • Outputs can be classified according to two characteristics 1. Their distribution type (inside or outside) and the people who read and use them. 2. Their implementation methods • Output type – – Internal External Both (internal and external) Turnaround (external outputs reenter the systems as input) Irwin/Mc. Graw-Hill 10 Copyright © 2004 The Mc. Graw-Hill Companies. All Rights reserved

SYSTEMS ANALYSIS AND DESIGN METHODS 6 th Edition Whitten Bentley Dittman Implementation Methods for Outputs • Printed output using paper (Still the most popular) – Tabular output presents information in columns. – Zoned output places text and numbers into designated areas • Screen output – Graphic output is the use of pictorial charts to convey information and demonstrate trends and relationships that cannot be easily seen in tabular formats. • • • Point-of-sale terminals Multimedia E-mail Hyperlinks Microfilm or microfiche Irwin/Mc. Graw-Hill 16 Output Design Copyright © 2004 The Mc. Graw-Hill Companies. All Rights reserved

SYSTEMS ANALYSIS AND DESIGN METHODS 6 th Edition Whitten Bentley Dittman Output Design Guidelines 1. Outputs should be simple to read and interpret. – Include a title. – Date and time stamp. – Include sections and headings to segment information. – Clearly label all fields and columns. – Include legends for all abbreviations. – Include only required information. Online provide methods to expand contract information. – Report information in format that does not have to be manually edited. – Information should be balanced across the page or screen. – Provide for easy navigation. – Avoid computer jargon and error messages. Irwin/Mc. Graw-Hill 17 Copyright © 2004 The Mc. Graw-Hill Companies. All Rights reserved

SYSTEMS ANALYSIS AND DESIGN METHODS 6 th Edition Whitten Bentley Dittman Output Design Guidelines 2. The timing of outputs is important. • This can affect how the output is designed an implemented 3. The distribution of (or access to) outputs must be sufficient to assist all relevant users. • The choice of implementation method affects distribution 4. Outputs must be acceptable to the system users who will receive them. • Systems analyst must understand how the recipient plans to use the output See page 599 – 607… Irwin/Mc. Graw-Hill 18 Copyright © 2004 The Mc. Graw-Hill Companies. All Rights reserved

SYSTEMS ANALYSIS AND DESIGN METHODS 6 th Edition Whitten Bentley Dittman C H A P T E R 16 Irwin/Mc. Graw-Hill 19 INPUT DESIGN AND PROTOTYPING Copyright © 2004 The Mc. Graw-Hill Companies. All Rights reserved

SYSTEMS ANALYSIS AND DESIGN METHODS 6 th Edition Whitten Bentley Dittman Input Implementation Methods • • • Keyboard Mouse Touch Screen Point-of-sale terminals Sound and speech Automatic data capture – Optical mark recognition (OMR) • Bar codes – – – Optical character recognition (OCR) Magnetic Ink Electromagnetic transmission Smart cards Biometric Irwin/Mc. Graw-Hill 20 Copyright © 2004 The Mc. Graw-Hill Companies. All Rights reserved

SYSTEMS ANALYSIS AND DESIGN METHODS 6 th Edition Whitten Bentley Dittman Input Design Guidelines • Capture only variable data. – Not data that can be looked up. • Do not capture data that can calculated or stored in computer programs as constants. – Extended Price (quantity * price), Federal Withholding, etc. • Use codes for appropriate attributes. Irwin/Mc. Graw-Hill 21 Copyright © 2004 The Mc. Graw-Hill Companies. All Rights reserved

SYSTEMS ANALYSIS AND DESIGN METHODS 6 th Edition Whitten Bentley Dittman Source Document / Form Design Guidelines • Include instructions for completing the form. • Minimize the amount of handwriting. • Data to be entered (keyed) should be sequenced top-tobottom and left-to-right. • When possible use designs based on known metaphors. Irwin/Mc. Graw-Hill 22 Copyright © 2004 The Mc. Graw-Hill Companies. All Rights reserved

SYSTEMS ANALYSIS AND DESIGN METHODS 6 th Edition Whitten Bentley Dittman Input Prototype for Video Title Maintenance Irwin/Mc. Graw-Hill 25 Copyright © 2004 The Mc. Graw-Hill Companies. All Rights reserved