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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 techniques 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 modules
2. Prototyping
Prototyping tests system concepts and provide an opportunity to examine input, output, and user interface before final decisions are made
Early working version of an information system
3. CASE Tools
Also called computer-aided software engineering, is a technique that uses powerful software, called CASE tools, to help systemsanalysts develop and maintain information
systems.
Framework for systems development and
support a wide variety of design methodologies
Coding Process
Coding is the process of turning program logic into specific instructions that the computer
system can execute.
Working from a specific design, a programmer uses a programming language to transform
program logic into code statements.
An individual programmer might create a small program, while larger programs typically are divided into modules that several individuals or groups can work on simultaneously
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
To simplify the integration of system components and reduce code development time, many programmers use an integrated development environment (IDE).
IDEs can make it easier to program interactivesoftware products by providing built-in tools and advanced features, such as real-time error detection, syntax hints, highlighted code, class browsers, and version control.
IBM WebSphere and Microsoft .NET are popular
IDEs.
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.
5.2 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
Getting a software quality assurance test done before making your website live will help you in plugging in all the loopholes that could cause losses to your business.
Types Of Software 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.
Test data should contain both correct data and
erroneous data and should test all possible situations that could occur
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
During testing, programmers can use softwaretools to determine the location and potential causes of program errors.
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 validatescustomer credit status, and a separate programthat updates data in thecustomer master file
Only by performing integration testing for this pair of programs can you make sure that the programs work together properly.
System Testing
Regardless of how the system was developed, system testing has the following 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
• 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
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
– 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.
• System developers also use defect tracking
software, sometimes called bug tracking
software, to document and track program
defects, code changes, and replacement code,
called patches.
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.
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.
• In this type of environment, the IT operations
staff serves as the first point of contact when
users experience problems with the system.
Operations documentation contains all the information needed for processing and distributing online and printed output.
Typical operations documentation includes the
following information:
Program, systems analyst, programmer, and
system identification
Scheduling information for printed output, such
as report run frequency and deadlines
Input files and where they originate; and output
files and destinations
E-mail and report distribution lists
– Special forms required, including online forms
Error and informational messages to operators
and restart procedures
Special instructions, such as security
requirements
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.
User documentation includes the following:
– A system overview that clearly describes all major system features, capabilities, and limitations
– Description of source document content,
preparation, processing, and samples
– Overview of menu and data entry screen options,
contents, and processing instructions
– Examples of reports that are produced regularly
or available at the user’s request, including
samples
– Security and audit trail information
– Explanation of responsibility for specific input,
output, or processing requirements
– Procedures for requesting changes and reporting
problems
– Examples of exceptions and error situations
– Frequently asked questions (FAQs)
– Explanation of how to get help and procedures
for updating the user manual
TOPIC 5.3 SYSTEM IMPLEMENTATION
SYSTEM IMPLEMENTATION
Managing systems implementation involvesapplication development, testing,
documentation, training, data conversion,
system changeover, and post-implementation
evaluation of the results.
During systems implementation, the systemdesign 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.
• Before a changeover, the system must be tested
and documented carefully, users must be
trained, and existing data must be converted.
System Installation & Evaluation
The new system now is ready to go to work.
Your earlier design activities produced theoverall architecture and processing strategy, andyou consulted users at every stage ofdevelopment.
You developed and tested programs individually,in groups, and as a complete system.
You prepared the necessary documentation andchecked it for accuracy, including support material for IT staff and users.
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
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.
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.
Otherwise, IT department members have no
reason to access the day-to-day operational
system.
• The test environment for an information system
contains copies of all programs, procedures, and
test data files.
Before making any changes to an operational system, you must verify them in the test
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.
• 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 orhardware, 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
Many vendors offer Web-based training options,
including 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 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.
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
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
nteractive 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 tutorials
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.
• 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
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
method for implementing commercial software packages
Cyclical information systems usually are
converted using the direct cutover method at thebeginning of a quarter, calendar year, or fiscal
year
– parallel operation
Easier to verify that the new system is working
properly under parallel operation than underdirect 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 theorganization, usually using the direct cutover
method
– 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
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
• 5.4 System Support & Security
System Support & Security Phase
Managing systems support and security involves
three main concerns:
– user expectations
– system performance
– security requirements .
The systems support and security phase begins
when a system becomes operational and continues until the system reaches the end of its
useful life
After delivering the system, the IT team focuses
on support and maintenance tasks
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
A help desk 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
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 support and troubleshooting.
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
Adapting the system to changing requirements; and
making the system operate more efficiently
System Maintenance Tools
• 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.
