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CHAPTER 5 SYSTEM IMPLEMENTATION AND SUPPORT - Coggle Diagram
CHAPTER 5
SYSTEM IMPLEMENTATION AND SUPPORT
5.1 System Development
System Development Tools
Systems analysts must know how to use a variety of technique such as modeling,prototyping,and computer-aided systems engineering tools to plan,design,and implement information systems.
1.Modeling
Modeling produces a graphical representation of a concept or process that system developers can analyze,test,and modify.Modeling Used to describe and simplify an information system:
• Business model or Requirements model
– Describes the information that a system must provide
Data model
Describes the data structure and design.
Object model
– Describes objects, which combine data and processes
Network model
– Describes the design and protocols of telecommunication links
Process model
– Describes the logic that programmers use to write code module
2.Prototyping
Prototyping tests system concepts and provide an opportunity to examine input, output, and user interface before final decisions are made.
CASE tools
computer-aided software engineering, is a technique that uses powerful software, called CASE tools, to help systems analysts develop and maintain information systems
Coding Process
Coding is the process of turning program logic into specific instructions that the computer system can execute
Programming Environment
Each IT department has its own programming
environment and standards.
Generating Code
You learned in earlier chapters that systems analysts use application generators, report writers, screen generators, fourth-generation languages, and other CASE tools that produce code directly from program design specifications
5.2 Testing In A Project
Software Quality Assurance
Importance of software quality assurance
Knowing that the quality of your software is up to the mark is extremely important.Studies have shown that most installations arenot done right just in the first time.
Types Of Software Testing
Unit testing
The testing of an individual program or module is
called unit testing.
Integration testing
Testing two or more programs that depend on each other is called integration testing, or link testing.
system testing
After completing integration testing, you must perform system testing, which involves the entire information system.
Documentation
Documentation describes an information system and helps the users, managers, and IT staff who must interact with it
Documentation includes
-Program documentation
Program documentation describes thr inputs,output,and processing logic for all program modules
– System documentation
System documentation describes the system’s
functions and how they are implemented.
– Operations documentation
If the information system environment involves a minicomputer, a mainframe, or centralized servers, the analyst must prepare documentation for the IT group that supports centralized operations.
– User documentation
User documentation consists of instructions and information to users who will interact with the system and includes user manuals, Help screens, and tutorials
5.4 System Support & Security
• Managing systems support and security involves
three main concerns:
– user expectations
– system performance
– security requirements .
User support
Companies provide user support in many forms,including user training and a help desk to provide technical support and assistance
User training (Package)
Depending on the nature of the changes, the package could include online support via e-mail, a special Web site, a revision to the user guide, a training manual supplement,or formal training sessions.
Help Desk
A help desk is a centralized resource staffed by IT professional who provide users with the support they need to do their jobs.
A help desk has three main objectives:
Show people how to use system resources more effectively,
Provide answers to technical or operational questions
Make users more productive by teaching them how to meet their own information needs.
Types of maintenance
Maintenance activities include:
Changing programs, procedures, or documentation to ensure correct system performance.
Adapting the system to changing requirements; and making the system operate more efficiently.
System Maintenance Tools
Many CASE tools include system evaluation and maintenance
features, including the following examples:
• Performance monitor that provides data on program execution times
• Program analyzer that scans source code, provides data element cross-reference information, and helps evaluate the impact of a program change
• Interactive debugging analyzer that locates the source of a programming error
• Reengineering tools
• Automated documentation
• Network activity monitor
• Workload forecasting tool
System Security
System security refers to protecting the system from theft,unauthorized access and changes, and accidental or accidental harm. In automated systems, security involves protecting all the parts of computer system which includes data, software, and hardware. systems security includes system privacy and system integrity
System Security concept
Confidentiality protects information from unauthorized disclosure and safeguards privacy
Integrity prevents unauthorized users from creating, modifying, or deleting information.
Availability ensures that authorized users have timely and reliable access to necessary information
Backup and Recovery
Backup refers to copying data at prescribed intervals, or continuously.
Recovery involves restoring the data and restarting the system after an interruption
5.3 System Implementation
Managing systems implementation involves application development, testing,documentation, training, data conversion,system changeover, and post-implementation evaluation of the results
System Installation & Evaluation
The new system now is ready to go to work.
Your earlier design activities produced the overall architecture and processing strategy, and you consulted users at every stage of development
• Remaining steps in systems implementation:
– Prepare a separate operational and test enviroment.
– 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
Operational & test environment
An environment, or platform, is a specific combination of hardware and software.
The environment for the actual system operation is called the operational environment or production enviroment.
Training
No system can be successful without proper training, whether it involves software, hardware, or manufacturing.
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
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
Webinars, Podcasts, and Tutorials
A Webinar, which combines the words Web andseminar, is an Internet-based training session that provides an interactive experience.
A podcast refers to a Web-based broadcast that allows a user to download multimedia files to a PC or portable device.
A tutorial is a series of online interactive lessons that present material and provide a dialog with users.
Outside Training Resources
You also can look into an independent training firm to provide in-house hardware or software 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 interacrive tutorials
– Rely on previous trainees
Interactive Training
– Usually, a relationship exists between training methods and costs
– Online training
• Should include step-by-step instructions
– Video tutorials
• You don’t have to be a professional video developer to create effective training tutorial
Data conversion
During data conversion, existing data is loaded
into the new system.
Depending on the system, data conversion can be done before, during, or after the operational environment is complete
system changeover
System changeover is the process of putting the new information system online and retiring the old system.
The four changeover methods are
– direct cutover
– Involves more risk than other changeover methods
– Companies often choose the direct cutover packages method for implementing commercial software
– Cyclical information systems usually are converted using the direct cutover method at the beginning of a quarter, calendar year, or fiscal year
– 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
– 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
– 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
Post-implementation task
Once the new system is operational, you must perform two additional tasks:
– Deliver a 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
• 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
– Prepare a 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