Information Systems Analysis and Design

1
Information Systems Analysis and Design
Information Systems
Section A
CHAPTER 9
PARSONS/OJA
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Information Systems Analysis and Design
Chapter 9
Chapter PREVIEW

• Information systems
• Types of information systems
• System development life cycle (SDLC)

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Information Systems
Section A
Chapter 9
What is an information system?

• An information system collects, stores, and
  processes data to provide useful, accurate, and
  timely information
• Information is used to make decisions

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Information Systems
Section A
Chapter 9
Who uses information systems?

• Top management makes decisions with long-range
  impact. Referred to as strategic planning
• Summarized information for entire company
• Mid-level managers set incremental goals that can
  be achieved in a year or lessa process referred
  to as tactical planning
• Information relevant to managers
  responsibilities
• Low-level managers are responsible for scheduling
  employees, ordering supplies, and other
  activities that make day-to-day operations run
  smoothlya process referred to as operational
  planning
• Detailed information

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Information Systems
Section A
Chapter 9
How do information systems help the people in
an organization?

• An information system can help the people in an
  organization perform their jobs more quickly and
  effectively by automating routine tasks
• Online banking
• One of the major functions of an information
  system is to help people make decisions in
  response to problems
• Price for flight from Dallas to Chicago on
  Southwest

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Information Systems
Section A
Chapter 9
Do organizations require different kinds of
information systems?

• Because organizations have different missions,
  face different threats, and encounter different
  opportunities, they require different kinds of
  information systems

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Information Systems
Section A
Chapter 9
Types of information systems

• Office automation systems
• Transaction processing systems
• Management information system
• Decision support system
• Expert systems
• Neural networks
• Data base mining

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Information Systems
Section A
Chapter 9
Office Automation Systems

• An office automation system automates, or
  computerizes, routine office tasks
• Reorder of inventory

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Information Systems
Section A
Chapter 9
Transaction Processing Systems Whats a
transaction?

• A transaction is an event that requires a manual
  or computer-based activity
• Order a cheeseburger at McDonalds
• Most modern transaction processing systems use
  online processing. Such systems are often
  referred to as OLTPS (online transaction
  processing systems)
• Adding/dropping classes at EIU

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Information Systems
Section A
Chapter 9
What are common examples of transaction
processing systems?

• A point-of-sale (POS) system records items
  purchased at each cash register, and calculates
  the total amount due for each sale
• An order-entry/invoice system provides a way to
  input, view, modify, and delete customer orders
• A general accounting system records the financial
  status of a business by keeping track of income,
  expenses, and assets
• An e-commerce system collects orders and
  processes credit card payments

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Information Systems
Section A
Chapter 9
Management Information Systems What is a
management information system?

• A management information system (MIS) refers to a
  type of information system that uses the data
  collected by a transaction processing system, but
  manipulates that data to create reports that
  managers can use to make routine business
  decisions in response to structured problems

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Information Systems
Section A
Chapter 9
What is a management information system?

• One of the major goals of an MIS is to increase
  the efficiency of managerial activity
• A summary report combines or groups data and
  often shows totals
• Top management
• An exception report contains information that is
  outside of normal or acceptable ranges
• Middle management regions where GM SUV sales
  below monthly forecast
• Scheduled reports follow a fixed format and are
  produced according to a preset timetable
• An ad hoc report is a customized report,
  generated to supply specific information not
  available in scheduled reports
• Impact of SARS on airlines at Torontos airport

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Information Systems
Section A
Chapter 9
How does an MIS differ from a TPS?

• Whereas a TPS simply records data, an MIS can
  consolidate data by grouping and summarizing it
• TPS provides raw material
• MIS is finished product

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Information Systems
Section A
Chapter 9
What are the limitations of a management
information system?

• A traditional MIS is based on the data collected
  by a transaction processing system
• Employee morale
• The reports generated by an MIS are limited by
  the processing capabilities of the database
  software.
• The MIS cannot typically be used to create models
  or projections

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Information Systems
Section A
Chapter 9
Decision Support Systems Whats a decision
support system?

• A decision support system (DSS) helps people make
  decisions by directly manipulating data,
  analyzing data from external sources, generating
  statistical projections, and creating data models
  of various scenarios

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Information Systems
Section A
Chapter 9
Whats a decision support system?

• A DSS does not make decisions, however. That
  task remains the responsibility of the human
  decision maker
• A decision model is a numerical representation of
  a realistic situation
• A decision query is a question or set of
  instructions describing data that must be
  gathered to make a decision
• Pujols has hit .537 against left handed pitchers
• A DSS typically includes modeling tools so
  managers can create a numerical representation of
  a situation and explore what-if alternatives

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Information Systems
Section A
Chapter 9
What are the limitations of a DSS?

• A DSS helps people manipulate the data necessary
  to make a decision, but does not actually make a
  decision
• A DSS is appropriate in situations where it is
  used by trained professionals

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Information Systems
Section A
Chapter 9
Expert Systems What is an expert system?

• An expert system, sometimes referred to as a
  knowledge-based system, is a computer system
  designed to analyze data and produce a
  recommendation, diagnosis, or decision based on a
  set of facts and rules
• The facts and rules for an expert system are
  typically derived by interviewing one or more
  experts, and then incorporated into a knowledge
  base
• What percent of my portfolio should be invested
  in stocks?

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Information Systems
Section A
Chapter 9
Expert Systems What is an expert system?

• Use data base of knowledge to draw conclusions
• Data base is If, Then knowledge
• Rules of thumb provided by expert individuals
• Can handle routine situations with great
  accuracy leaves complex situations to humans
• Can explain why it reached conclusion loan
  denied because
• Each expert system is designed to make decisions
  in a particular area or domain
• Credit card fraud, HP printer support

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Information Systems
Section A
Chapter 9
Neural networks

• An expert system begins with a set of facts and
  rules. But if the rules are not known, a
  computer can learn how to make decisions based
  on hundreds or thousands of lightning-fast trial
  and error attempts
• A neural network uses computer circuitry to
  simulate the way a brain might process
  information, learn, and remember
• Looks for patterns that work
• May use genetic algorithms where only the best
  solutions survive

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Information Systems
Section A
Chapter 9
Neural networks are used when

• There are not hard and fast solutions such as
  pattern recognition and forecasting
• Neural nets are well suited to problems that
  people are good at solving, but for which
  computers are not.
• What are the characteristics of a terrorist?

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Information Systems
Section A
Chapter 9
Data base mining

• automated extraction of predictive information
  from large databases
• What customer will respond to a catalog of bird
  feed and houses?
• Deep Blue used data mining to calculate all
  possible moves and selected best move
• Confirming or discovering patterns in huge data
  bases

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Information Systems
Section A
Chapter 9
Data base mining

• Pattern validation
• Confirm existence of expected patterns.
• Visits to Health Service in November versus
  September
• Top down data mining
• May not ask about the right patterns.
• Pattern discovery
• 75 of the purchasers of low-fat ice cream buy
  bottled water

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Systems Analysis
Section B
Chapter 9
What is a system development life cycle?
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Systems Analysis
Section B
Chapter 9
Planning Phase How does an information system
project begin?

• An information system project begins with a
  planning phase
• The goal of these activities is to create a
  Project Development Plan
• This planning document includes
• A short description of the project, including its
  scope
• A justification for the project
• A list of project team participants
• A schedule for the project, including an outline
  of its phases

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Systems Analysis
Section B
Chapter 9
Justify Project Why are new information
systems developed?

• The justification for a new information system
  usually emerges from a serious problem with the
  current system, or from an opportunity to improve
  an organizations products or services using
  technology
• Perhaps your network cant handle traffic trying
  to use the Internet at peak times

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Systems Analysis
Section B
Chapter 9
Analysis Phase What happens in the analysis
phase?

• The goal of the analysis phase is to produce a
  list of requirements for a new or revised
  information system

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Systems Analysis
Section B
Chapter 9
Is it really important to understand the
current system before planning a new system?

• Typically, a new information system is designed
  to replace a system or process that is already in
  place
• It is important to study the current system to
  understand its strengths and weaknesses before
  planning a new system

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Systems Analysis
Section B
Chapter 9
Determine System Requirements How does the
project team determine what the new system should
do?

• System requirements are the criteria for
  successfully solving the problem or problems
  identified in an information system
• They also serve as an evaluation checklist at the
  end of the development project, so they are
  sometimes called success factors

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Systems Analysis
Section B
Chapter 9
What marks the end of the analysis phase of the
SDLC?

• The analysis phase concludes when the project
  team produces a written report that documents its
  findings
• The System Requirements Report typically contains
  diagrams that illustrate what the new information
  system should do
• Should we do the same thing when we buy a
  personal computer?

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System Design
Section C
Chapter 9
Design Phase What happens in the design phase?

• In the design phase of the SDLC, the project team
  must figure out HOW the new system will fulfill
  the requirements specified in the System
  Requirements Report

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System Design
Section C
Chapter 9
Identify Potential Solutions How does the
project team come up with solutions?

• There might be more than one way to solve the
  problems and meet the requirements identified in
  the analysis phase of the SDLC
• The project team should identify several
  potential hardware and software solutions by
  brainstorming and researching case studies on
  Web sites and in computer magazines

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System Design
Section C
Chapter 9
What kinds of hardware alternatives are
available?

• A myriad of hardware options are available for
  information systems
• Mainframes, servers, and personal computers are
  the most commonly used components, but in some
  information systems, handhelds, or even
  supercomputers, play a role

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System Design
Section C
Chapter 9
What kinds of software alternatives are
available?

• The project team might consider software
  alternatives, such as whether to construct the
  system from scratch, use an application
  development tool, or commercial software
• Creating an information system from scratch
  using a programming language can take many months
  or years
• An application development tool is essentially a
  type of software construction kit containing
  building blocks that can be assembled into a
  software product

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System Design
Section C
Chapter 9
What kinds of software alternatives are
available?

• Commercial software for an information system is
  usually a series of pre-programmed software
  modules, supplied by a software developer,
  consulting company, or value-added reseller (VAR)
• A turnkey system is essentially an information
  system in a box which consists of hardware and
  commercial software designed to offer a complete
  information system solution
• A turnkey system must be extensively evaluated to
  determine whether it can satisfy system
  requirements

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System Design
Section C
Chapter 9
Evaluate Solutions and Select the Best How
does the team choose the best solution?

• To determine the best solution the project team
  devises a list of criteria for comparing each of
  the potential solutions
• Each criterion is assigned a weight to indicate
  its importance. The project team then evaluates
  the criteria for each solution and assigns raw
  scores
• Sound complicated? It isnt, especially if the
  project team uses a decision table

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System Design
Section C
Chapter 9
Select Hardware and Software How does the
project team find the right hardware and software
for the new information system?

• Once the project team selects a solution, the
  next task is to select the hardware and software
  needed to implement the solution
• The method for selecting the hardware, software,
  and vendor depends on the project teams
  understanding of what is required for the solution

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System Design
Section C
Chapter 9
Develop Application Specifications What
happens after the project team selects a solution?

• Exactly what happens next in the system design
  phase depends on the type of solution selected
• If the project team selected a solution that
  requires custom programming, the teams systems
  analysts will create a set of application
  specifications

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System Design
Section C
Chapter 9
What happens to the completed specifications?

• Application specifications are similar to the
  pages of an architectural blueprint that show the
  detailed plan for electrical wiring or plumbing
• In a large information systems project, the
  specifications are given to a programming team or
  application developer who creates the software
• In a small information systems project, you as
  the user might develop your own specifications

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Implementation and Maintenance
Section D
Chapter 9
Implementation Phase What happens during the
implementation phase?

• During the implementation phase of the SDLC, the
  project team supervises the tasks necessary to
  construct the new information system

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Implementation and Maintenance
Section D
Chapter 9
Purchase and Install Hardware and Software Do
most new information systems require new hardware?

• Most new information systems require new
  hardware, which can either replace old equipment,
  or be connected to existing equipment

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Implementation and Maintenance
Section D
Chapter 9
How about new software?

• Many information systems require new software,
  such as a commercial application, a programming
  language, an application development tool, or an
  expert system shell

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Implementation and Maintenance
Section D
Chapter 9
Test Applications How can the team ensure that
a new information system works?

• A rigorous testing process is the only way to
  make sure that a new information system works

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Implementation and Maintenance
Section D
Chapter 9
What is application testing?

• Application testing is the process of trying out
  various sequences of input values and checking
  the results to verify that the application works
  correctly
• As each application module is completed, it
  undergoes unit testing to ensure that it operates
  reliably and correctly
• When all modules have been completed and tested,
  integration testing is performed to ensure that
  the modules operate together correctly

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Implementation and Maintenance
Section D
Chapter 9
Train Users How do employees learn how to use
the new information system?

• In preparation for using a new information
  system, users need extensive training, which
  might include hardware operation, data entry, and
  backup procedures
• Training sessions can be conducted by members of
  the team or professional trainers
• Resistance to change!!!

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Implementation and Maintenance
Section D
Chapter 9
Convert to New System How does a business
switch from the old system to the new system?

• System conversion refers to the process of
  deactivating an old information system and
  activating the new one
• A direct (crash) conversion means that the old
  system is completely deactivated and the new
  system is immediately activated
• A parallel conversion avoids some of the risk
  because the old system remains in service while
  some or all of the new system is activated
• In a phased conversion, the new system is
  activated one module at a time

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Implementation and Maintenance
Section D
Chapter 9
How does a business switch from the old system
to the new system?

• A pilot conversion works well in organizations
  with several branches that have independent
  information processing systems
• The new information system is activated at one
  branch
• If the system works correctly at one branch, it
  is activated at the next branch

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Implementation and Maintenance
Section D
Chapter 9
Maintenance Phase What happens during the
maintenance phase?

• The maintenance phase of the SDLC involves
  day-to-day operation of the system, making
  modifications to improve performance, and
  correcting problems
• The maintenance phase of the SDLC is the most
  expensive because it lasts until the system is
  retired

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Implementation and Maintenance
Section D
Chapter 9
Why do maintenance activities include user
support?

• Even after-in-depth training, employees sometimes
  forget procedures, or have difficulty when they
  encounter a new set of circumstances
• Many organizations establish a help desk to
  handle end-user problems

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Implementation and Maintenance
Section D
Chapter 9
Does an information system change during the
maintenance phase?

• The term maintenance phase is a bit misleading
• Changes during the maintenance phase typically
  include the following
• Upgrades to operating system and commercial
  software
• User interface revisions
• Application software revisions
• Hardware replacements
• Security upgrades

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Implementation and Maintenance
Section D
Chapter 9
When does the maintenance phase end?

• The maintenance phase continues until an
  information system is no longer cost effective,
  or until changes in the organization make the
  information system obsolete
• Then cycle begins again with the development of a
  replacement system

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