Systems Analysis and Design 9 Edition Chapter 11

Systems Analysis and Design 9 Edition Chapter 11

Systems Analysis and Design 9 Edition Chapter 11 Managing Systems Implementation th Phase Description Systems Implementation is the fourth of five phases in the systems development life cycle Includes application development, documentation, testing, training, data

conversion, and system changeover The deliverable for this phase is a completely functioning information system 2 Chapter Objectives Explain the importance of software quality assurance and software engineering Describe the application development process for structured, object-oriented, and agile methods

Draw a structure chart showing top-down design, modular design, cohesion, and coupling 3 Chapter Objectives Explain the coding process Explain unit, integration, and system testing Differentiate between program, system, operations, and user documentation List the main steps in system installation and evaluation

4 Chapter Objectives Develop training plans for various user groups, compare in-house and outside training, and describe effective training techniques Describe data conversion and changeover methods Explain post-implementation evaluation and the final report to management

5 Introduction The system design specification serves as a blueprint for constructing the new system The initial task is application development Before a changeover can occur, the system must be tested and documented carefully, users must be trained, and existing data must be converted A formal evaluation of the results takes place as part of a final report to management 6

Software Quality Assurance Software Engineering Capability Maturity Model (CMM) Capability Maturity Model Integration (CMMI) Process improvement CMMI tracks an organization's processes, using five maturity layers

7 Software Quality Assurance International Organization for Standardization (ISO) Many firms seek assurance that software systems will meet rigid quality standards ISO 90003:2004

ISO requires a specific development plan 8 Overview of Application Development Application development Objective is to translate the design into program and code modules that will function properly Review the System Design Tasks produced an overall design and a plan for

physical implementation 9 Overview of Application Development Application Development Tasks Traditional methods Start by reviewing documentation from prior SDLC phases and creating a set of program designs At this point, coding and testing tasks begin Agile Methods

Intense communication and collaboration will now begin between the IT team and the users or customers Objective is to create the system through an iterative process 10 Overview of Application Development System Development Tools Entity-relationship diagrams Flowcharts

Pseudocode Decision tables and decision trees 11 Overview of Application Development Project Management Even a modest-sized project might have hundreds or even thousands of modules Important to set realistic schedules, meet project deadlines, control costs, and maintain quality

Should use project management tools and techniques 12 Structured Application Development Structure Charts

Control module Subordinate modules Module Data Couple Control Couple Condition Loop 13

Structured Application Development Cohesion and Coupling If you need to make a module more cohesive, you can split it into separate units, each with a single function Loosely coupled Tightly coupled 14

Structured Application Development Drawing a Structure Chart Step 1: Review the DFDs Review all DFDs for accuracy and completeness Step 2: Identify Modules and Relationships Transform functional primitives or object methods into program modules Three-level structure charts relate to the three DFD levels

15 Structured Application Development Steps in Drawing a Structure Chart Step 3: Add Couples, Loops, and Conditions Identify the data elements that pass from one module to another Step 4: Analyze the Structure Chart and the Data Dictionary Ensure that the chart reflects all previous documentation and that the logic is correct

16 Object-Oriented Application Development Object-oriented development (OOD) Characteristics of Object-Oriented Application Development The application's structure is represented

by the object model itself 17 Object-Oriented Application Development Implementation of Object-Oriented Designs Main objective is to translate object methods into program code modules and determine what event or message will trigger the execution of each module Object-Oriented Cohesion and Coupling

Classes loosely coupled Methods loosely coupled and highly cohesive 18 Agile Application Development Is a distinctly different systems development method Development team is in constant communication with the customer Focuses on small teams, intense communication, and rapid development

iterations Extreme Programming (XP) is one of the newest agile methods 19 Agile Application Development An extreme programming (XP) Example User story Release plan Iteration cycle Iteration planning meeting Parallel programming

Test-driven design 20 Agile Application Development The Future of Agile Development Critics claim it lacks discipline and produces systems of questionable quality Before implementing agile development, the proposed system and development methods should be examined carefully A one-size-fits-all solution does not exist

21 Coding Coding Programming Environments Integrated development environment (IDE) Generating Code Can generate editable

program code directly from macros, keystrokes, or mouse actions 22 Testing the System Unit Testing Integration Testing System Testing You should regard thorough testing as a cost-effective means of

providing a quality product 23 Documentation Program Documentation

System Documentation Operations Documentation User Documentation Systems analysts usually are responsible for preparing documentation to help users learn the system 24 Documentation User Documentation Effective online

documentation is an important productivity tool Written documentation material also is valuable 25 Management Approval After system testing is complete, you present the results to management If system testing produced no technical,

economical, or operational problems, management determines a schedule for system installation and evaluation 26 System Installation and Evaluation Remaining steps in systems implementation: Prepare a separate operational and test environment Provide training for users, managers, and IT staff Perform data conversion and system changeover

Carry out post-implementation evaluation of the system Present a final report to management 27 Operational and Test Environments 28 Operational and Test Environments The operational environment includes

hardware and software configurations and settings, system utilities, telecommunications resources, and any other components that might affect system performance If you have to build or upgrade network resources to support the new system, you must test the platform rigorously before system installation begins 29 Training Training Plan

The three main groups for training are users, managers, and IT staff You must determine how the company will provide training Vendor Training Often gives the best return on your training dollars 30

Training Vendor Training If the system includes the purchase of software or hardware, then vendor-supplied training is one of the features you should investigate in the RFPs (requests for proposal) and RFQs (requests for quotation) that you send to potential vendors Often gives the best return on your training dollars 31

Training Webinars, Podcasts, and Tutorials Webcast Subscribers As technology continues to advance, other wireless devices such as PDAs and cell phones will be able to receive podcasts Tutorials can be developed by software vendors, or by a companys IT team 32

Training Outside Training Resources Many training consultants, institutes, and firms are available that provide either standardized or customized training packages 33

Training Training Tips Train people in groups, with separate training programs for distinct groups Select the most effective place to conduct the training Provide for learning by hearing, seeing, and doing Prepare effective training materials, including interactive tutorials Rely on previous trainees 34

Training Interactive Training Usually, a relationship exists between training methods and costs Online training Should include step-by-step instructions Video tutorials You dont have to be a professional video developer to create effective training tutorials

35 Data Conversion Data Conversion Strategies The old system might be capable of exporting data in an acceptable format for the new system or in a standard format such as ASCII or ODBC If a standard format is not available, you must develop a program to extract the data and convert it Often requires additional data items, which might require manual entry

36 Data Conversion Data Conversion Security and Controls You must ensure that all system control measures are in place and operational to protect data from unauthorized access and to help prevent erroneous input Some errors will occur It is essential that the new system be loaded with accurate, error-free data

37 System Changeover 38 System Changeover Direct Cutover Involves more risk than other changeover methods Companies often choose the direct cutover method for implementing commercial software

packages Cyclical information systems usually are converted using the direct cutover method at the beginning of a quarter, calendar year, or fiscal year 39 System Changeover Parallel Operation Easier to verify that the new system is working properly under parallel operation than under direct cutover Running both systems might place a burden on the

operating environment and cause processing delay Is not practical if the old and new systems are incompatible technically Also is inappropriate when the two systems perform different functions 40 System Changeover Pilot Operation The group that uses the new system first is called the pilot site The old system continues to operate for the entire

organization After the system proves successful at the pilot site, it is implemented in the rest of the organization, usually using the direct cutover method Is a combination of parallel operation and direct cutover methods 41 System Changeover Phased Operation You give a part of the system to all users The risk of errors or failures is limited to the

implemented module only Is less expensive than full parallel operation Is not possible, however, if the system cannot be separated easily into logical modules or segments 42 System Changeover 43 Post-Implementation Tasks

Post-Implementation Evaluation A post-implementation evaluation should examine all aspects of the development effort and the end product the developed information system You can apply the same fact-finding techniques in a post-implementation evaluation that you used to determine the system requirements during the systems analysis phase 44 Post-Implementation Tasks

Final Report to Management Your report should include the following: Final versions of all system documentation Planned modifications and enhancements to the system that have been identified Recap of all systems development costs and schedules 45 Post-Implementation Tasks Final Report to Management Your report should include the following:

Comparison of actual costs and schedules to the original estimates Post-implementation evaluation, if it has been performed Marks the end of systems development work 46 Chapter Summary The systems implementation phase consists of application development, testing, installation, and

evaluation of the new system Analysts and technical writers also prepare operations documentation and user documentation Develop a training program A post-implementation evaluation assesses and reports on the quality of the new system and the work done by the project team 47 Chapter Summary The final report to management includes the final system documentation, describes any

future system enhancements that already have been identified, and details the project costs The report represents the end of the development effort and the beginning of the new systems operational life Chapter 11 complete 48

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