Computers: Information Technology in Perspective By Long and Long Copyright 2002 Prentice Hall, Inc. Developing Business Information Systems Chapter 11

Quit 12.2 The System Life Cycle BirthDeathDevelopmentProduction

Quit 12.3 Application Software Purchase a proprietary software package Buy it Use an application service provider (ASP) Rent it Develop a custom information system Make it

Quit 12.4 System Development Techniques  Structure chart encourages top-down design PayrollSystemPayrollSystem EmployeeDatabaseEmployeeDatabaseReportProcessReportProcessGeneralLedgerGeneralLedger CreationCreationMainte-nanceMainte-nanceHourlyHourlySalarySalary System Development Structured System Design

Quit 12.5 System Development Techniques Entity Symbol Process Flow line Data Storage Data Flow Diagram: Focus is on information flow Entity Relationship Diagram: Focus is on attributes of entities and relationship between them. Web Site Web Site

Quit 12.6 System Development Techniques Combination of symbols and flow lines portrays the logic of the program or system Main Program LoopSubroutines Flowcharting Online Storage Input/ Output Display Printed Output Computer Process Predefined Process No Yes Terminal Point Decision

Quit 12.7 Computer-Aided Software Engineering  CASE tools Design tools Design tools Information repository tools Information repository tools Program development tools Program development tools  Software Engineers  Custom Programs Courtesy of Federal Express Corporation. All rights reserved.

Quit 12.8 CASE Tool Kit Contains  Design tools User interface User interface Screen generator Screen generator Layout Layout Report generator Report generator  Information repository tools Cross-referencing system (database) Cross-referencing system (database) Packages system documentation Packages system documentation  Program development tools Application Generator Application Generator Generation of text data Generation of text data

Quit 12.9Prototyping  Developing Prototype Systems Scalable Systems Scalable Systems System Specifications (Specs) System Specifications (Specs) Functional Specifications Functional Specifications  Three Objectives Analyze current situation Analyze current situation Identify information needs Identify information needs Develop a model of the target system Develop a model of the target system  Rapid Application Development (RAD) Monthly Technology Update

Quit System Conversion  Systems and acceptance testing Unit testing Unit testing Systems testing Systems testing Uses test data and then live data Uses test data and then live data  Approaches to system conversion Parallel conversion Parallel conversion Direct conversion Direct conversion Phased conversion Phased conversion Pilot conversion Pilot conversion

Quit System Implementation System becomes operational! System maintenance starts Patches necessary Computers at Work

Quit 12.12Programming  A program solves a problem Uses logic Uses logic Design program logic before writing it Design program logic before writing it Nothing more than a set of instructions Nothing more than a set of instructions  Programming Languages: Machine Language Machine Language Procedure-Oriented: COBOL Procedure-Oriented: COBOL Object-Oriented (OOP): Smalltalk and C++ Object-Oriented (OOP): Smalltalk and C++ Fourth Generation (4GL) Fourth Generation (4GL) Visual Programming: Visual BASIC Visual Programming: Visual BASIC

Quit Writing the Program  System specification review  Program identification and description  Coding, testing, and documentation

Computers: Information Technology in Perspective By Long and Long Copyright 2002 Prentice Hall, Inc. Developing Business Information Systems The End