Chapter 22 Systems Design Implementation and Operation Copyright

Chapter 22 Systems Design, Implementation, and Operation Copyright © 2012 Pearson Education, Inc. publishing as Prentice Hall 22 -1

Learning Objectives Discuss the conceptual systems design process and the activities in this phase. Discuss the physical systems design process and the activities in this phase. Discuss the systems implementation and conversion process and the activities in this phase. Discuss the systems operation and maintenance process and the activities in this phase. Copyright © 2012 Pearson Education, Inc. publishing as Prentice Hall 22 -2

Systems Development Life Cycle (SDLC) System Analysis Operations & Maintenance Implementation & Conversion Copyright © 2012 Pearson Education, Inc. publishing as Prentice Hall Conceptual Design Physical Design 22 -3

Conceptual Design Developer creates a general framework for implementing user requirements and solving the problems identified in the analysis phase. Evaluating design alternatives Preparing design specifications Preparing the conceptual systems design report Copyright © 2012 Pearson Education, Inc. publishing as Prentice Hall 22 -4

Preparing Design Specifications Output How often? What should reports contain? What should reports look like? Should reports be online or hard copy or both? Data Storage What data elements must be stored to produce a report? How they should be stored? What type of file or database should be used? Input Where, when, and how to collect the data? Processing Procedures and Operations Copyright © 2012 Pearson Education, Inc. publishing as Prentice Hall 22 -5

Physical Design Conceptual designs are translated into detailed specifications that are used to code and test the computer programs. Output File and database Input Program Procedures Controls Copyright © 2012 Pearson Education, Inc. publishing as Prentice Hall 22 -6

Output Design Determine the nature, format, content, and timing of reports, documents, and screen displays. Types of Output: Scheduled reports Special-purpose analysis reports Triggered exception reports Demand reports Copyright © 2012 Pearson Education, Inc. publishing as Prentice Hall 22 -7

Program Design 1. Determine user needs. 2. Create and document development plan. 3. Write program instructions (code the system). 4. Test the program (debug for errors). 5. Document the program. 6. Train the users. 7. Install the system. 8. Use and modify the system. Copyright © 2012 Pearson Education, Inc. publishing as Prentice Hall 22 -8

Procedures and Controls Procedures for who, what, where, why, when: Input preparation Transaction processing Error detection and correction Controls Reconciliation of balances Database access Output preparation and distribution Computer operator instructions Copyright © 2012 Pearson Education, Inc. publishing as Prentice Hall Control considerations: Validity Authorization Accuracy Security Numerical control Availability Maintainability Integrity Audit control 22 -9

Implementation and Conversion Process of installing hardware and software and getting the AIS up and running Planning Prepare site Train personnel Complete documentation Test system Conversion Copyright © 2012 Pearson Education, Inc. publishing as Prentice Hall 22 -10

Types of Documentation Development Documentation A system description; copies of output, input, and file and database layouts; program flowcharts; test results; and user acceptance forms Operations Documentation Includes operating schedules; files and databases accessed; and equipment, security, and file-retention requirements User Documentation Teaches users how to operate the AIS; it includes a procedures manual and training materials Copyright © 2012 Pearson Education, Inc. publishing as Prentice Hall 22 -11

Types of System Testing Walk-Through Step-by-step reviews of procedures or program logic to find incorrect logic, errors, omissions, or other problems Processing Test Data Using both valid transactions and all possible error conditions Acceptance Tests Real transactions and files rather than hypothetical ones, users develop the acceptance criteria and make the final decision whether to accept the AIS Copyright © 2012 Pearson Education, Inc. publishing as Prentice Hall 22 -12

Types of Conversions Direct Terminates the old AIS when the new one is introduced Parallel Operates the old and new systems simultaneously for a period Phase-in Gradually replaces elements of the old AIS with the new one Pilot Implements a system in one part of the organization, such as a branch location Localizes conversion problems and allows training in a live environment Copyright © 2012 Pearson Education, Inc. publishing as Prentice Hall 22 -13

Operations and Maintenance Post-Implementation Review Determines whether the system meets its planned objectives Copyright © 2012 Pearson Education, Inc. publishing as Prentice Hall 22 -14