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SYSTEM IMPLEMENTATION AND SUPPORT - Coggle Diagram
SYSTEM IMPLEMENTATION AND SUPPORT
SYSTEM DEVELOPMENT TOOLS
System 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 system.
Modeling
graphical representation of a concept or process that system developers can
analyze, test, and modify.
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 modules.
Prototyping
tests system concepts and provide
an opportunity to examine input, output, and
user interface before final decisions are made.
pros
Speeds up the
development process
significantly.
Users can identify needed changes and refine real
requirements.
cons
Important decisions might be made too early, before business or IT issues are
thoroughly understood.
Users can identify needed changes and refine real
requirements.
CASE Tools
called 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
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.
Visual Basic, Python, Ruby, and SQL are examples of commonly used programming languages, and many commercial packages use a proprietary set
of commands.
Generating Code
systems
analysts use application generators, report writers, screen generators, fourth-generation languages, and other CASE tools that produce code directly from program design specifications.
Some commercial applications can generate editable program code directly from macros, keystrokes, or mouse actions
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 are
not done right just in the first time.
This result to incurring of damage repair
expenses. You can avoid this by hiring a professional testing company that will test your software and give your software quality assurance.
3 Types Of Software Testing
Unit testing
Integration testing
System testing
Unit testing
The testing of an individual program or module is
called unit testing.
The objective is to identify and eliminate execution errors that could cause the program to terminate abnormally, and logic errors that could have been missed during desk checking.
Integration testing
Testing two or more programs that depend on each other is called integration testing, or link testing.
For example, consider an information system with a program that checks and validates customer credit status, and a separate program that updates data in the customer master file.
System Testing
After completing integration testing, you must perform system testing, which involves the entire information system.
A system test includes all typical processing situations and is intended to assure users, developers, and managers that the program meets all specifications and that all necessary features have been included.
Documentation
describes an information system and helps the users, managers, and IT staff who must interact with it.
Accurate documentation can reduce system downtime, cut costs, and speed up maintenance tasks.
Documentation is essential for successful system
operation and maintenance.
4 Documentation includes
program documentation
system documentation
operations documentation
user documentation
Program documentation
describes the inputs, outputs, and processing logic for all program modules.
n process starts in
the systems analysis phase and continues during systems implementation.
system documentation
describes the system’s
functions and how they are implemented.
n includes data dictionary
entries, data flow diagrams, object models, screen
layouts, source documents, and the systems
request that initiated the project.
operation 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.
A mainframe installation might require the scheduling of batch jobs and the distribution of printed reports.
user documentation
consists of instructions and
information to users who will interact with the system and includes user manuals, Help screens,and tutorials.
The skill set required to develop documentation usually is not the same as that to develop a systems.
Technical writing requires specialized skills, and competent technical writers are valuable members of the IT team.
SYSTEM IMPLEMENTATION
Managing systems implementation involves application development, testing, documentation, training, data conversion, system changeover, and post-implementation evaluation of the results.
During systems implementation, the system design specification serves as a blueprint for constructing the new system.
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.
You developed and tested programs individually,
in groups, and as a complete system.
5 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.
5.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 environment.
The environment that analysts and programmers use to develop and maintain programs is called the test environment.
Training
No system can be successful without proper training, whether it involves software, hardware, or manufacturing.
A successful information system requires training for users, managers, and IT staff members.
The entire systems development effort can depend on whether or not people understand the system and know how to use it effectively.
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.
You should develop a data conversion plan as early as possible, and the conversion process should be tested when the test environment is developed.
System changeover
is the process of putting the
new information system online and retiring the
old system.
Changeover can be rapid or slow, depending on
the method.
four changeover methods
direct cutover
parallel operation
pilot operation
phased operation
Post-implementation task
Once the new system is operational, you must
perform two additional tasks:
Prepare a post-implementation evaluation.
Deliver a final report to management.
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
SYSTEM SUPPORT & SECURITY
Managing systems support and security involves
three main concerns:
user expectations
system performance
security requirements
Successful, robust systems often need the most
support
In most organizations, more than half of all ITdepartment effort goes into supporting existing
systems.
User Support
Companies provide user support in many forms, including user training and a help desk to provide
technical support and assistance.
User Training
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.
Training users about system changes
is similar to initial training.
The main objective is to show users how the system can help them perform their jobs.
Help Desks
is a centralized resource staffed by IT professionals 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.
can boost its productivity by using remote control software, which allows IT staff to take over a user’s workstation and provide support and troubleshooting.
2 Types Of Maintenance
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 privacy deals with protecting people systems from being accessed and used without the permission/information of the concerned individuals.
System integrity is concerned with the quality and reliability of raw
as well as processed data in the system.
BACKUP AND RECOVERY
Backup refers to copying data at prescribed intervals, or continuously.
Regular backup of databases daily/weekly depending on the time criticality
and size.
Incremental back up at shorter intervals.
Backup copies stored in secure remote place particularly necessary for
disaster recovery.
Duplicate systems run and all transactions mirrored if it is a very critical system and cannot tolerate any disruption before storing in disk.
Recovery involves restoring the data and restarting the system after an
interruption.