Information Systems

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Information Systems A system A syste A
SYSTEM is a set of items (components, equipment,
process, etc) linked together to carry out a
given task in order to
achieve one or more objectives. .
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Information Systems

• An information system is a mechanism that helps
  people collect, store, organize, and use
  information. This is the primary use for
  computers.
• An information system can be manual, like a card
  catalog or an address book or computerized.
• Computerized information systems can range from a
  simple database of names to a satellite-tracking
  system.
• All information systems, regardless of their
  type, serve the same purpose to help users get
  a certain type of value from their information.

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Information systems differ in their business
needs depending upon different levels in the
organization.
Executive Support Systems
Expert Systems
Office automation
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Types of Information Systems

• Office Automation Systems
• Transaction Processing Systems
• Management Information Systems
• Decision Support Systems
• Expert Systems
• Executive Support Systems

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Office Automation Systems

• -Office Automation is the use of computer systems
  to execute a variety of office operations, such
  as word processing, accounting, e-mail etc.
  Office automation (OA) is regarded as being of
  major importance in improving business efficiency
  in most institutions especially financial
  institutions. OASs systems are also used to
  automate routine office tasks, such as
• (a) (creation of documents,)document
  preparation
• (b) the billing ,
• (c) personal information management
  (message distribution)
• (d) information retrieval
•  

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Transaction Processing Systems

• i) Transaction processing system is a system that
  handles data created by the organisations
  business activities.
• ii) TPS can also be defined as computerised
  system that performs and records the daily
  routine transactions of the Business
  activities.
• It captures, stores and transmits details of
  business transactions such as sales, purchases,
  invoices, etc.
• A transaction is an event that can occur as a
  series of steps, such as taking and fulfilling an
  order from a customer.

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Transaction Processing Systems

• Transaction Processing System supports
  operational managers and provides them with daily
  routine transactions, thereby helping them keep
  track of the elementary activities or
  transactions of the organisation.
• In other words, TPS provide the raw materials
  needed by other information systems such as MIS.

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Transaction Processing Systems

• An example of Transaction Processing System would
  be an Order Processing System which captures
  customer details, order specifications and
  processes this data.

MIS (management reports)
Order processing system
Order file
Government Agencies
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• Typically, an order file would contain such data
  as customer particulars, order number, discount,
  quantity etc. This data would be immediately
  captured by Order Processing System (TPS) which
  would contain accurate and up-to-date sales data
  on the sales master file.(see types of files)
• This information is then captured by middle
  managers who make reports on the transactions of
  the business at the end of the period. This data
  will also be available immediately to Government
  agencies for purposes of tax.

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• Another example can be the payroll system.
• A payroll system keeps track of money paid to
  employee.
• Employee details such employee time card with the
  employees name, Social Security number, number
  of hours worked etc represent a single
  transaction for this system.
• Once this transaction is input into the
  system, it updates the systems file that
  permanently maintains employee information for
  the organization. (master file)

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Management Information Systems

• i) Management Information System (MIS) is a
  system which helps middle management with
  monitoring, controlling, decision-making, and
  administrative activities.
• ii) Management Information System can also be
  defined as a set of computer programs that use
  data from recorded transactions (from a
  Transaction Processing System) as input and
  produce summary and routine reports as output.

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• A management information system (MIS) is designed
  to provide information that is designed for use
  by different types of managers by meeting the
  needs of managers at different levels. As
  senior-level managers need different types of
  information than mid- or low-level managers.
  These people may need entirely different types of
  information, or to view the same type of
  information in unique ways.
• In other words, it summarises data from TPS into
  reports that reflect the performance of the
  Business/ Organisation.

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• Both manual and computerized information
  processing can be divided into two broad types
  namely batch and real time processing. Batch
  processing are becoming less common.
• Batch Processing System
• Batch processing systems, this is a system where
  data is collected, accumulated for a certain
  interval period of time such as weekly or
  monthly, and then these transactions are captured
  as a unit in order to update the related master
  file.

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• Examples of systems that use batch are water
  billing , final accounts preparation, payroll
  system(i.e. Batch processing system would
  collect data from various departments about
  employees names, time worked, rate of pay, etc
  and will then be processed into salaries/ pay at
  the month-end.) and even final examination
  results utilizes this type of system.
• other examplesstudents

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• Advantages of batch processing. 
• Time is available to check and correct errors.
• No special equipment or software is required,
  therefore, the available hardware and software
  can adapt to the type of processing.
• It contributes to large-scale economies due to
  bulk processing.
• System design is simple
• It cheaper than employing real time processing.
• Processing can be done in parts and the remainder
  later.
•  
• Disadvantages.
• If errors go without being checked the entire
  information may be affected resulting in the
  re-input of data.
• Delay is introduced in organizing data in batches
  hence resulting in managements required
  information not up to date.
• Preparing batches result in duplication of
  effort.

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Real time processing

• Real time processing occurs when data is
  collected and captured right away so that the
  results of the processing are known immediately.
• Real time processing means that there is no delay
  between the inputs of the transaction to the
  C.P.U and the updating of the master file. Real
  time may require on line facilities because the
  C.P.U must always be available to accept the data
  and update the master file Real time processing
  involves transaction being input and processed
  immediately, in real-time .
• On-line refers to the input of the transactions
  while the input device is connected directly to
  the main central processing unit of the system.

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Real time processing

• The term on-line is also used to describe an
  active Internet connection.
• On-line-Real time processing is appropriate when
  immediate processing is required and the delay
  implicit in batch processing would not be
  acceptable.
• Examples of On-line systems include the
  following
• -in a department store or a supermarket
• - in banking and credit card systems
• - booking systems

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Examples of On-line systems

• a) As a sale is made in a department store
  or a supermarket, the bar code on the merchandise
  is scanned at the Point-of-sale system/ terminal
  that is directly connected to the central machine
  in the supermarket or at the head office in order
  to facilitate on-line-real time processing.
• b) In banking and credit card systems,
  customer details are often maintained in a
  real-time environment whereby there is an
  immediate access to customer balances, credit
  position and authorization for withdrawals

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• C) booking systems
• Travel agents, airlines and theatre
  ticket agencies all use real time systems. Once
  a hotel room, plane seat or theatre seat is
  booked up everyone on the system must know about
  it immediately so that they do not sell the same
  holiday or seat to two or more different
  customers
• Advantages.
• Management information is up to date.
• There is no delay in processing as it is done
  instantaneously e.g. accounting enquiries can be
  dealt with while the customer is on the phone/
  on-line, simply by inputting the customers
  records on the V.D.U
• Information is more readily available because the
  master file is on line.

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• Disadvantages.
• A computer used for real time application cannot
  be used for anything else
• Systems are much more complex than in other forms
  of processing or demand processing
• Because data files are immediately updated,
  errors maybe more damaging and security becomes
  an important consideration.
• Hardware and software costs are more expensive

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Decision Support Systems

• Decision-support systems ("DSS") are specifically
  designed to help management make decisions in
  situations where there are uncertainties about
  the possible outcomes of those decisions. DSS
  comprise tools and techniques to help gather
  relevant information and analyse the options and
  alternatives. DSS often involves use of complex
  spreadsheet and databases to create "what-if"
  models.

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Decision Support Systems

• A decision support system may use data from a
  organisation's transaction processing system or
  from external sources, such as stock market
  reports, information about competitors, and so
  on.
• A decision support system collects various types
  of business data, which is used to generate
  special reports that help managers make
  decisions.
• These systems provide highly tailored, structured
  reports that can be used for very specific
  business situations.
• DSS does not make decisions but merely guides
  managers through a process to make a decision

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Customers and Supplies
Competition and global markets
Governmental
External Data Sources
Input and feedback
Interaction
Decision Support Software Mathematical modeling
tools Database manager
Manager or Staff Specialist
Query, model and analysis results
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The nature of Decision-making

• There are two types of decisionsstructured
  unstructured
• Structured decisions are those that are made,
  following a set of rules and guidelines
• Decisions are objective
• Solutions are clear
• There is always the right answer
• Unstructured decisions are those made
  subjectively
• You may also have semi-structured decisions which
  lies between structured and unstructured

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Types of decision-makesrs in DSS

• There are two groups of decision-makers, namely..
• Analytic decision-maker follows set of rules,
  uses graphs, statistics, probability theory etc
• Heuristic decision-maker uses rule of thumb,
  experience, common sense, trial error etc
• (Computing proceeding/s to a solution by trial
  and error.)
• Note that DSS will have sub systems e.g
  spreadsheets, graphics, statistical analysis ,
  databases etc
• DSS is aimed at serving strategic managers
  although all managers can also use it.

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Characteristics a DSS

• Provide support for semi or unstructured
  decision-making
• Provide support for decision-making to management
  
• Should be user friendly
• Provide support for decisions that are
  interdependent as well as those that are
  independent
• Provide support for all stages of decision-making
  processes

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Executive Support Systems/Executive IS
Executive Support Systems (ESS). These are a relatively new category of systems that support decision making by senior management. ESS - is designed to help senior management make strategic decisions They serve at strategic level of the organization. Although they have limited capabilities they employ the most advanced graphics and can deliver graphs and data from many sources immediately to senior executives offices or boardrooms. ESS gathers, analyses and summarizes the key internal and external information used in the business. They are oriented towards external events, although they do take summarized information from MIS and DSS. A good way to think of an ESS is to imagine the senior management team in an aircraft cockpit - with the instrument panel showing them the status of all the key activities. ESS typically involve lots of data analysis and modeling tools such as "what-if" analysis to help strategic decision-making.
 

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Characteristics of Executive Information Systems

• Ability to filter out and summaries data from the
  main data
• Ability to drill down to specific areas
• Ability to manipulate summary data
• Has built-in graphics, charts, etc
• Availability of templates
• Availability of analysis tools

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Expert Systems

• An expert system is a specialized information
  system that performs tasks normally done by
  people, such as making decisions.
• An expert system is a computer program that
  encapsulates the knowledge of one or more human
  experts. It can store facts and rules about a
  specific area of knowledge, and can then use this
  knowledge base to deliver advice to a user. For
  example, an expert system used by the
  construction industry stores thousands of facts
  and rules governing costs associated with
  constructing various types of building, taking
  into account type of ground, floor area, number
  of heating required and so on. When a
  construction company wants to work out the
  estimated cost of a new building, they enter the
  requirements and the expert system comes up with
  a cost. (This is traditionally the job of a
  quantity surveyor, who would take several days to
  perform the complex calculations manually that
  the expert system can do in a matter of seconds.)
• Medical diagnosis is another field well suited to
  the capabilities of an expert system.

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• Components of an expert system
• An expert system has three basic components
• A knowledge base containing all the facts and
  rules associated with the subject
• An inference engine, which is the means of using
  that knowledge. This could be,
• for example, a program written in Prolog
• A user interface to provide straightforward
  communications between the user and
• the computer.
• Characteristics of an ES
• It stores the facts and rules associated with a
  particular field knowledge.
• It asks the user questions relevant to the
  problem (e.g. how many storeys will the
• building have?).
• It can handle dont know answers.
• It allows the user to change an answer to explore
  a what-if situation.
• It makes reasonable deductions.
• It explains how it reaches its conclusion.
•  

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Advantages of an expert system The knowledge is
always on tap (available) whereas a human
expert is not always there when you need one. An
expert system may, in a few seconds, be able to
reach a conclusion based on complex calculations
that would take a human days or week to
perform. It bases its decisions purely on logic
emotion does not come into play. Disadvantages
of an expert system It is inflexible in certain
circumstances, the application of pure logic may
be detrimental. For example, if an expert system
were used to determine sentences for criminal
offenders, it may not take account of exceptional
circumstances which it has not encountered. A
human expert who uses an expert system may be
reluctant to contradict a decision even though
his/her instincts may dictate otherwise. For
example a doctor may accept a diagnosis for fear
of litigation. A human may become over-reliant on
the expert system, and rubber-stamp its decisions
without thinking about them.
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Knowledge Management Systems
Knowledge Management Systems ("KMS") exist to
help businesses create and share information.
These are typically used in a business where
employees create new knowledge and expertise -
which can then be shared by other people in the
organization to create further commercial
opportunities. Good examples include firms of
lawyers, accountants and management
consultants. KMS are built around systems which
allow efficient categorization and distribution
of knowledge. For example, the knowledge itself
might be contained in word processing documents,
spreadsheets, PowerPoint presentations. internet
pages or whatever. To share the knowledge, a KMS
would use group collaboration systems such as an
intranet.
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The Role of the IS Department

• The Information Systems (IS) department is
  responsible for designing, building, and managing
  an organization's information systems.
• In years past, the IS department served only the
  informational needs of managers. Today, the IS
  team supports all workers in a business, and
  supports the business' mission, as well.
• In conclusion, an IS task include designing,
  planning, installing, and maintaining systems
  generating reports and cost control.

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Role Players in an IS Department

• An IS department can include many members with
  many different skills. A large IS staff may
  include

Managers Purchasing Agents Computer
Scientists Security Managers Systems
Analysts Trainers Programmers User Assistance
Architects Database Specialists Technical
Writers System or Network Managers Hardware
Maintenance Technicians