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 Conceptual Design Physical Design Implementation & Conversion Operations & Maintenance Copyright © 2012 Pearson Education, Inc. publishing as Prentice Hall 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  Control considerations:  Validity  Authorization  Accuracy  Security  Numerical control  Availability  Maintainability  Integrity  Audit control Copyright © 2012 Pearson Education, Inc. publishing as Prentice Hall 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