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.
.
Information Systems
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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 differ in their business needs depending upon different levels in the organization.
Executive Support Systems
Expert Systems
Office automation
Types of Information Systems
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Office Automation Systems
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Transaction Processing Systems
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Management Information Systems
Decision Support Systems
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Expert Systems
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Executive Support Systems
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
Transaction Processing Systems
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
• 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.
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
• 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.
• 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)
Management Information Systems
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i) Management Information System (MIS) is a system
which helps middle management with monitoring,
controlling, decision-making, and administrative
activities.
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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.”
• 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.
• 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.
• 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
• 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.
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• 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.
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.
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
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.
• 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
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.
Decision Support Systems
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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
Governmental
Customers and
Supplies
Competition and
global markets
External Data Sources
Input and feedback
Interaction
Manager or
Staff Specialist
Decision Support
Software
Mathematical modeling tools
Database manager
Query, model and
analysis results
The nature of Decision-making
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There are two types of decisions:structured & unstructured
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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
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Unstructured decisions are those made subjectively
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You may also have semi-structured decisions which lies
between structured and unstructured
Types of decision-makesrs in DSS:
There are two groups of decision-makers, namely..
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Analytic decision-maker – follows set of rules, uses graphs,
statistics, probability theory etc
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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.
Characteristics a DSS :
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Provide support for semi or unstructured decision-making
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Provide support for decision-making to management
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Should be user friendly
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Provide support for decisions that are interdependent as well as those
that are independent
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Provide support for all stages of decision-making processes
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.
Characteristics of Executive Information Systems
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Ability to filter out and summaries data from the main data
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Ability to drill down to specific areas
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Ability to manipulate summary data
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Has built-in graphics, charts, etc
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Availability of templates
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Availability of analysis tools
Expert Systems
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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.
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 ‘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.
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.
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.
The Role of the IS Department
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The Information Systems (IS) department is
responsible for designing, building, and managing an
organization's information systems.
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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.
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In conclusion, an IS task include designing, planning,
installing, and maintaining systems; generating
reports; and cost control.
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