16 Chapter 16: Making the System Operational Systems Analysis and Design in a Changing World, 3 rd Edition 16 Systems Analysis and Design in a Changing World, 3rd Edition 2 Learning Objectives ◆ Describe implementation and support activities ◆ Choose an appropriate approach to program development ◆ Describe various types of software tests and explain how and why each is used 16 Systems Analysis and Design in a Changing World, 3rd Edition 3 Learning Objectives (continued) ◆ List various approaches to data conversion and system installation and describe the advantages and disadvantages of each ◆ Describe different types of documentation and the processes by which they are developed and maintained ◆ Describe training and user support requirements for new and operational systems 16 Systems Analysis and Design in a Changing World, 3rd Edition 4 Overview ◆ This chapter focuses on activities of implementation and support phases of systems development life cycle (SDLC) ◆ Implementation activities occur before system is turned over to users ◆ Implementation consumes more time and resources than earlier phases of the SDLC ◆ Support activities occur after system becomes operational and may continue for years 16 Systems Analysis and Design in a Changing World, 3rd Edition 5 Activities of the Implementation and Support Phases 16 Systems Analysis and Design in a Changing World, 3rd Edition 6 Program Development ◆ Program development is time consuming ● One-third of development labor ● One-third to one-half of project development schedule ◆ Programming and testing considerations: ● Required resources ● Managerial complexity ● System quality 16 Systems Analysis and Design in a Changing World, 3rd Edition 7 Order of Implementation ◆ Input, process, output (IPO) development order ● Based on data flow through system ● Simplifies testing ● User interfaces developed early to reduce change ● Disadvantage is late implementation of outputs ◆ Structured design – IPO order based on system flowchart and structure chart ◆ OO design – IPO order in package diagrams 16 Systems Analysis and Design in a Changing World, 3rd Edition 8 Order of Implementation (continued) ◆ Top-down and bottom-up order from traditional structured design and structured programming ◆ Top-down begins with top structure chart module ● Always a working version of program ● Requires three or more iterations to complete ◆ Bottom-up begins with modules at lowest level of structure chart ● Many programmers can begin immediately ● Requires driver programs to test 16 Systems Analysis and Design in a Changing World, 3rd Edition 9 System Flowchart for a Payroll System 16 Systems Analysis and Design in a Changing World, 3rd Edition 10 Structure Chart for a Payroll System [...]... Important planning considerations q Costs of operating both systems in parallel q Detecting and correcting errors in new system q Potentially disrupting the company and IS operations q Training personnel and customers with new procedures 33 16 Direct Installation x New system installed and quickly made operational x Overlapping systems turned off x Both systems concurrent for brief time x Advantage: simplicity... state interactions 28 16 System Testing x Tests the behavior of the entire system q Build and smoke test is performed daily to discover any problems with daily builds q Performance test checks time-based requirements q Acceptance test is performed to determine whether system meets user requirements 29 16 Data Conversion x Data needed at system startup q Files or databases of system being replaced q... Manual records q Files or databases of other systems q User feedback during normal system operation x Reuse of existing databases x Reloading database contents x Creating new databases 30 Two Approaches to Reloading Database Content After a Structural Modification 16 31 16 A Complex Data-Conversion Example 32 16 Installation x After development and testing, system must be put into operation x Important... testing costs by 50% 21 16 Testing x Process of examining a product to determine if any defects exist x Testing levels are related to specific SDLC phases x Testing activities spread throughout SDLC x Most of testing takes place following software construction and definition of defect standards 22 16 Generic Model of Software Testing 23 Correspondence Between SDLC Phases and Various Types of Testing 16. . .16 Package Diagrams for RMO Subsystems 11 16 Package Diagram for Three-Layer OO 12 16 Construction and Test Plan x Development order x Testing order x Data used to test modules, module groups, methods, classes, programs, and subsystems x Acceptance criteria x Relevant personnel assignments (construction and testing) 13 16 Framework Development x When developing large OO systems, object... Phases and Testing Activities Performed Within Each Phase 16 25 16 Test Cases x Important part of testing is specifying test cases and data x Test cases specify one or more events to which software must respond q q Events to which software responds q x Starting state Expected response or ending state Analysis phase documentation is useful in preparing test cases 26 16 Unit Testing x Testing individual... Disadvantage: risk due to no backup 34 16 Parallel Installation x Old and new systems operated together for extended period of time x Advantages: low risk of system failure and continually backup x Disadvantage: cost to operate both systems q Hiring temporary personnel q Acquiring extra space q Increasing managerial and logistical complexity 35 16 Phased Installation x New system installed in series of steps... simplify testing and support q Alpha Version – incomplete testing version q Beta Version – end user testing version q Production Release Version – formally distributed to users or made operational q Maintenance Release – bug fixes, small changes 18 16 Description of Versions for RMO 19 16 Quality Assurance x Process of ensuring information system meets minimum quality standards x Determined by users,... individual modules of code or methods before integration with other software x Driver module used for testing q q Calls module to be tested and passes input parameters q x Sets values of input parameters Accepts return parameters from tested module Stub testing – test module simulates module not yet developed 27 16 Integration Testing x Tests the behavior of a group of modules or methods x Test both normal... parts of the system and across applications q Assigned to best programmers and thoroughly tested 14 16 Team-Based Program Development x Management Issues q q Task assignment to specific teams or members q x Organization of programming teams Member and team communication and coordination Variety of different models used for organization 15 Comparison and Summary of Development Team Types 16 16 16 Source . 16 Chapter 16: Making the System Operational Systems Analysis and Design in a Changing World, 3 rd Edition 16 Systems Analysis and Design in a Changing. after system becomes operational and may continue for years 16 Systems Analysis and Design in a Changing World, 3rd Edition 5 Activities of the Implementation and Support Phases 16 Systems. types of documentation and the processes by which they are developed and maintained ◆ Describe training and user support requirements for new and operational systems 16 Systems Analysis and Design