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SYSTEM IMPLEMENTATION AND SUPPORT - Coggle Diagram
SYSTEM IMPLEMENTATION AND SUPPORT
5.1 System Development
System Development Tools
Systems analysts must know how to use a variety
of techniques such as modeling, prototyping,and computer-aided systems engineering tools to plan, design, and implementinformation systems.
Systems analysts work with these tools in a team
environment, where input from users, managers, and IT staff contributes to the system design.
Modeling
Modeling produces a graphical representation of a concept or process that system developers can analyze, test, and modify.
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 modules
CASE Tools
Also called computer-aided software
engineering, is a technique that uses powerful software, called CASE tools, to help systems analysts develop and maintain information systems.
Framework for systems development and
support a wide variety of design methodologies
Prototyping
Prototyping tests system concepts and provide
an opportunity to examine input, output, and user interface before final decisions are made.
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.
Visual Basic, Python, Ruby, and SQL are examples
of commonly used programming languages, and many commercial packages use a proprietary set of commands.
As the trend toward Internet-based applications
continues, HTML/XML, Java, and other Web-centric languages will be used extensively
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.
Some commercial applications can generate
editable program code directly from macros, keystrokes, or mouse actions.
5.4 System Support & Security
System Support & Security Phase
Managing systems support and security involves
three main concerns:
system performance
security requirements
user expectations
Successful, robust systems often need the most
support
In most organizations, more than half of all IT
department effort goes into supporting existing systems
User Support
Companies provide user support in many forms,
including user training and a help desk to providetechnical support and assistance.
User Training
Depending on the nature of the
changes, the package could includeonline 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
A help desk is a centralized resource staffed by IT professionals who provideusers 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.
A help desk can boost its productivity by using remote control software, which allows IT staff to take over a user’s workstation and provide supportand troubleshooting.
Types Of Maintenance
Adapting the system to changing requirements; and
making the system operate more efficiently.
Changing programs, procedures, or documentation
to ensure correct system performance.
System Maintenance Tools
Many CASE tools include system evaluation and maintenance features, including the following examples
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
Performance monitor that provides data on program execution times
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.
5.3 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.
The initial task is application development, which
requires systems analysts and programmers to work together to construct the necessary programs and code modules.
System Installation & Evaluation
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.
The new system now is ready to go to work.
Remaining steps in systems implementation
Provide training for users, managers, and IT
staff
Perform data conversion and system
changeover
Prepare a separate operational and test
environment
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 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.
Access to the operational environment is limited
to users and must strictly be controlled
Systems analysts and programmers should not
have access to the operational environment except to correct a system problem or to make authorized modifications or enhancements.
IT department members have no reason to access
the day-to-day operational system.
Otherwise, IT department members have no
reason to access the day-to-day operational system.
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.
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
Often gives the best return on your training
dollars
Webinars, Podcasts, and Tutorials
A Webinar, which combines the words Web and
seminar, is an Internet-based training session that provides an interactive experience.
A tutorial is a series of online interactive lessons
that present material and provide a dialog with users
Many vendors offer Web-based training options,
including Webinars, podcasts, and tutorials
Outside Training Resources
You also can look into an independent training
firm to provide in-house hardware or software training.
If vendor training is not practical and your
organization does not have the internal resources to perform the training, you might find that outside training consultants.
Many training consultants, institutes, and firms
are available that provide either standardized or customized training packages
Training Tips
Select the most effective place to conduct the
training
Provide for learning by hearing, seeing, and doing
Train people in groups, with separate training
programs for distinct groups
Prepare effective training materials, including
interactive tutorials
Rely on previous trainees
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.
If a standard format is not available, you must
develop a program to extract the data and convert it
It is essential that the new system be loaded
with accurate, error-free data
System changeover
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.
The four changeover methods are
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
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
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
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
Direct cutover is similar to throwing a switch that
instantly changes over from the old system to the new.
Parallel operation requires that both systems run
simultaneously for a specified period, which is the slowest method.
Post-implementation task
Once the new system is operational, you must
perform two additional tasks
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
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
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 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.
A software testing and quality assurance
company specifications and give you a report detailing out the findings.
Types Of Software Testing
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.
The output from the validation program
becomes input to the master file update program.
Only by performing integration testing for this
pair of programs can you make sure that the programs work together properly.
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.
Successful completion of system testing is the
key to user and management approval, which is why system tests sometimes are called acceptance tests.
Final acceptance tests, however, are performed
during systems installation and evaluation.
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.
For example, for a field that allows a range of
numeric values, the test data should contain minimum values, maximum values, values outside the acceptable range, and alphanumeric characters.
Documentation
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.
Documentation includes
system documentation
System documentation describes the system’s
functions and how they are implemented.
System documentation includes data dictionary
entries, data flow diagrams, object models, screen layouts, source documents, and the systems request that initiated the project.
System documentation is necessary reference
material for the programmers and analysts who must support and maintain the system.
Most of the system documentation is prepared
during the systems analysis and design phases.
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.
The skill set required to develop documentation
usually is not the same as that to develop a system.
Technical writing requires specialized skills, and
competent technical writers are valuable members of the IT team.
Just as you cannot throw a system together in
several days, you cannot add documentation at the end. That is a common misconception and often proves fatal to a project.
Regardless of the delivery method, user documentation must be clear, understandable, and readily accessible to users at all levels.
Systems analysts usually are responsible for
preparing documentation to help users learn the system.
User documentation includes
Description of source document content,
preparation, processing, and samples
Overview of menu and data entry screen options,
contents, and processing instructions
A system overview that clearly describes all major
system features, capabilities, and limitations
Examples of reports that are produced regularly
or available at the user’s request, including samples
Security and audit trail information
program documentation
Program documentation describes the inputs,
outputs, and processing logic for all program modules.
The program documentation process starts in
the systems analysis phase and continues during systems implementation.
Systems analysts prepare overall documentation,
such as process descriptions and report layouts, early in the SDLC.
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.
A mainframe installation might require the
scheduling of batch jobs and the distribution of printed reports.
In this type of environment, the IT operations
staff serves as the first point of contact when users experience problems with the system.
Typical operations documentation includes
Scheduling information for printed output, such
as report run frequency and deadlines
Input files and where they originate; and output
files and destinations
Program, systems analyst, programmer, and
system identification
E-mail and report distribution lists
Error and informational messages to operators
and restart procedures
Special instructions, such as security
requirements
