Information systems can be manual or computerized and serve to collect, organize, store, and distribute information. There are several types of information systems including transaction processing systems, management information systems, decision support systems, expert systems, executive support systems, and knowledge management systems. The information systems department is responsible for designing, implementing, and maintaining an organization's information infrastructure and systems to support business operations and informational needs.

1. Information SystemsA 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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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.
Information Systems

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

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Office Automation Systems
Transaction Processing Systems
Management Information Systems
Decision Support Systems
Expert Systems
Executive Support Systems
Types of Information Systems

5. -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
Office Automation Systems

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i) Transaction processing system is a system that
handles data created by the organisation’s 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.
Transaction Processing Systems

7. Transaction Processing Systems
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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.

8. 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.
Order file
Order processing
system
MIS (management
reports)
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
employee’s 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 system’s file that permanently maintains
employee information for the organization. (master file)

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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.”
Management Information Systems

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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.

15. • 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 examples…students

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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 management’s required information not up to
date.
Preparing batches result in duplication of effort.

17. Real time processing
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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.

18. Real time processing
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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

19. 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

22. 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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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
Decision Support Systems

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

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There are two types of decisions:structured &
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
The nature of Decision-making

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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.
Types of decision-makesrs in DSS:

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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
Characteristics a DSS :

28. 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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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
Characteristics of Executive Information Systems

30. • 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.
Expert Systems

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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 a
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 th
building have?’).
It can handle ‘don’t 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.

32. 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.

34. Knowledge Management
SystemsKnowledge 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 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.
The Role of the IS Department

36. An IS department can include many members with many
different skills. A large IS staff may include:
Managers Purchasing Agents
Computer ScientistsSecurity Managers
Systems Analysts Trainers
Programmers User Assistance Architects
Database Specialists Technical Writers
System or Network Managers
Hardware Maintenance Technicians
Role Players in an IS Department