2. Developing Information Systems 1 Copyright © 2001 by Harcourt, Inc. All rights reserved. Part 3

3. Systems Development Systems development Information system life cycle –Development –Effective operational use –Decline usefulness DevelopmentEffective Operational UseDecline Percent of Effectiveness

4. Systems Change - WHY? Growth Integration of Business Areas Better Security Gov’t Regulations Competition Technology Problems Greater Processing Speed Accuracy Faster Information Retrieval Reduce Cost

5. Who Involved? Management IS Personnel Users

6. Approaches to Development

7. Structured Systems Development Systems Development Life Cycle –Planning –Analysis –Design –Implementation

8. Structured Systems Development Systems development life cycle Planning Design AnalysisImplementation

9. Structured Systems Development Systems development life cycle

10. Structured Systems Development Waterfall development Planning Analysis Design Implementation

11. Planning Stage Identifying the project Initiating the project Performing a feasibility –Technical feasibility –Economic feasibility –Organizational feasibility –Stakeholder analysis Steps in the Planning Stage

12. Analysis Who will use the system? Where will the system be used? When will it be used? What are the requirements? Building logical models

13. Analysis Steps in the analysis stage Requirements Determination Model Building Understanding of What New System Must Do

14. Analysis How does the current system function, or what need will the new system meet? What data are needed for the revised or new system? What reports does the current system generate(if there is a current system)? How should the replacement or new system operate? What reports or results should the replacement or new system generate? How would the new system affect jobs of employees? Requirements Determination

15. Analysis Data model - Customer discount system Data model - Customer discount system *Customer ID Last Name First Name E-Mail Address Number Bucks (Other Columns) *Purchase Number Customer ID Product ID Price Paid Bucks Used Quantity Purchased Purchase Date *Product ID Product Name Current Product Price Product QOH

16. Analysis Data flow diagram - Customer discount system Data flow diagram - Customer discount system Customer Order System Module 1 Find available Bucks If>10, compute Net Amount and new Bucks Customer Data Find available Bucks Compute New Bucks and add to old Bucks Module 2 Net Amount Available Bucks Customer ID, Amount Available Bucks Updated Bucks Available Bucks Updated Bucks Available Bucks Customer ID, Amount