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Systems Analysis & Design(Sixth Edition)
Chapter 9Systems Implementation
PHASE 4: SYSTEMS IMPLEMENTATION
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Phase Description
Systems Implementation is the fourth of five phases in the systems development life cycle (SDLC)
Includes application development, testing, documentation, training, data conversion, system changeover, and post-implementation evaluation of the results
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Chapter Objectives
Explain the importance of software quality assurance and software engineering
Describe the application development process Draw a structure chart showing top-down design, modular
design, cohesion, and coupling Explain the coding process and how code is generated Explain unit testing, integration testing, and system testing
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Chapter Objectives
Differentiate between program, system, operations, and user documentation
List the main steps in system installation and evaluation
Develop an overall training plan with specific objectives for each group of participants, compare in-house and outside training providers, and describe effective training techniques
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Chapter Objectives
Describe the data conversion process Identify and describe changeover methods Explain post-implementation evaluation Describe the final report to management
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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
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Overview of Application Development
Application development Objective is to translate the logical design into
program and code modules that will function properly
Creation of the System Design The tasks involved in system design produced an
overall design and a plan for physical implementation
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Overview of Application Development
Application Development Steps Module Start by reviewing
documentation from prior SDLC phases and creating a set of program designs
After the design is created, coding can begin
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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
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Structured Application Development
Top-down approach Partitioning Modular design Constant input from programmers/IT management Ensure integration capability
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Structured Application Development
Structure Charts Structure charts show the program modules and the
relationships among them Control module Subordinate modules
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Structured Application Development
Structure Charts Module
Library module Data Couple Control Couple
Flag
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Structured Application Development
Structure Charts Condition
A condition line indicates that a control module determines which subordinate modules will be invoked, depending on a specific condition
Loop A loop indicates that one or more modules are
repeated
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Structured Application Development
Cohesion and Coupling Highly cohesive Loosely coupled
Tightly coupled
Status flag
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Structured Application Development
Structure Chart Examples
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Testing the System
After coding, a programmer must test each program to make sure that it functions correctly
Syntax errors Desk checking
Logic errors Structured walkthrough, or code review Design walkthrough
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Testing the System
Unit Testing Test data Unit Testing Stub Testing Test plan
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Testing the System
Integration Testing Integration testing, or link testing Testing the programs independently does not
guarantee that the data passed between them is correct A testing sequence should not move to the integration
stage unless it has performed properly in all unit tests
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Testing the System
System Testing - Major objectives: Perform a final test of all programs Verify that the system will handle all input data
properly, both valid and invalid Ensure that the IT staff has the documentation and
instructions needed to operate the system properly and that backup and restart capabilities of the system are adequate
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Testing the System
System Testing - Major objectives: Demonstrate that users can interact with the system
successfully Verify that all system components are integrated
properly and that actual processing situations will be handled correctly
Confirm that the information system can handle predicted volumes of data in a timely and efficient manner
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Testing the System
System Testing Called Acceptance tests You should regard thorough testing as a cost-effective
means of providing a quality product If conflicting views exist, management will decide
whether or not to install the system after a full discussion of the options
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Documentation
Documentation Program Documentation System Documentation Operations Documentation User Documentation
Online documentation
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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
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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
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Operational and Test Environments
The environment for the actual system operation is called the operational environment or production environment
The environment that analysts and programmers use to develop and maintain programs is called the test environment
A separate test environment is necessary to maintain system security and integrity and protect the operational environment
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Operational and Test Environments
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Training
Training Plan The first step is to identify who should receive training
and what training is needed The three main groups for training are users, managers,
and IT staff You must determine how the company will provide
training
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Training
Vendor Training If the system includes the purchase of software or
hardware, then vendor-supplied training is one of the features you should include 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
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Training
Outside Training Resources Many training consultants, institutes, and firms are
available that provide either standardized or customized training packages
You can contact a training provider and obtain references from clients
Center for the Application of Information Technologies (CAIT)
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Training
In-House Training The IT staff and user departments often share responsibility When developing a training program, you should keep the
following guidelines in mind: 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 Tutorial
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Training
In-House Training When developing a training program, you should keep
the following guidelines in mind: Rely on previous trainees Train-the-trainer strategy
When Training is complete, many organizations conduct a full-scale test, or simulation
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Data Conversion
Data Conversion Strategies Data Export – ASCII or ODBC Program Some manual entry
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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
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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
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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
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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
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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
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Post-Implementation Tasks
Post-Implementation Evaluation Includes feedback for the following areas:
Accuracy, completeness, and timeliness of information system output
User satisfaction System reliability and maintainability Adequacy of system controls and security measures Hardware efficiency and platform performance
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Post-Implementation Tasks
Post-Implementation Evaluation Includes feedback for the following areas:
Effectiveness of database implementation Performance of the IT team Completeness and quality of documentation Quality and effectiveness of training Accuracy of cost-benefit estimates and development
schedules
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Post-Implementation Tasks
Post-Implementation Evaluation When evaluating a system, you should:
Interview members of management and key users Observe users and computer operations personnel
actually working with the new information system Read all documentation and training materials Examine all source documents, output reports, and screen
displays Use questionnaires to gather information and opinions
form a large number of users Analyze maintenance and help desk logs
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Post-Implementation Tasks
Post-Implementation Evaluation Users can forget details of the developmental effort if too
much time elapses Pressure to finish the project sooner usually results in an
earlier evaluation in order to allow the IT department to move on to other tasks
Ideally, conducting a post-implementation evaluation should be standard practice for all information systems projects
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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 A 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
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Chapter Summary
Develop a training program Data conversion often is necessary when
installing a new information system System changeover is the process of putting
the new system into operation A post-implementation evaluation assesses
and reports on the quality of the new system and the work done by the project team
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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
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