1. Information Systems - What Are They?
Based on Chapter 1 of Bennett, McRobb and Farmer:
Object Oriented Systems Analysis and Design Using UML, (4th Edition), McGraw Hill, 2010.
© 2010 Bennett, McRobb and Farmer

2. In This Lecture You Will Learn:
How to define an information system (IS)
Some examples and types of IS
How to use the concepts of systems theory to explain the parts and behaviour of IS
How IS can be useful in managing organizations
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3. © 2010 Bennett, McRobb and Farmer
Introduction
Information systems (IS) are created by people
They are used in all kinds of organisations
They are important in our everyday lives
All IS must be able to select, store, process and retrieve relevant data
IS do not necessarily depend on digital IT (but most modern ones do)
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4. © 2010 Bennett, McRobb and Farmer
IS in History
IS have existed in some form throughout history:
Ancient Mesopotamian records of grain in city storehouses (3500 BCE)
Roman Empire records of property and tax
19th Century railway signalling systems
The RAF’s communication and control system used during the Battle of Britain(1940)
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5. The Emergence of Modern IS
Most IS today depend on digital electronic computers
Earliest examples (in Second World War) include code-breaking Colossus Computer
First business computer, Leo 1, built in 1951, used for routine transactions like payroll and managing inventory
Modern IS used for vast range of purposes
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6. The Role of the Computer
Computers carry out tasks also done by people and by other technologies
Storage: signalman’s memory / hard disk
Display: Battle of Britain map / PC screen
Calculation: abacus / software program
Communication: telephone line / LAN
Typical advantages of computers:
high speed, low cost, reliability
Worth stressing that most things computers do can also be done without them. Many examples of ‘information work’ long pre-date modern information technology – railway signalling is a good example, but there are many others.
Also worth getting the class to identify some disadvantages of using a computer. Examples:
Loss of human involvement in decisions
Inflexibility in unexpected circumstances
Poor analysis or design can make some tasks impossible to perform
Displacement of human skills
Fragmentation and automation of work can lead to loss of valuable communication about the work
© 2010 Bennett, McRobb and Farmer

7. McGregor On-Line Retail Site
A typical modern IS with:
Online catalogue display and shopping cart
Back-office systems store stock details, orders, payment transactions, and more
Communications link to credit-card processing centre
Robot warehouse control system
Delivery scheduling
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IS are Systems
© 2010 Bennett, McRobb and Farmer

9. Characteristics of Systems
Every system has:
Inputs and outputs
A purpose (related to transformation)
A boundary and an environment
Subsystems and interfaces
Control using feedback and feed-forward
Some emergent property
Emergent properties, in particular, will almost certainly need further explanation. One good example given by Ed Yourdon (I can’t remember the specific source) was the analyst who turned to a colleague and said “you are certainly more than the sum of your parts – you are an idiot!” The point being that if you look at the parts that make up a person, it would be difficult to find idiocy at any level of analysis other than a holistic view of the whole person.
A useful exercise would be for the class to suggest examples of systems and identify examples of each feature for these.
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Elements of an IS
Every IS must have:
A human activity that needs information
Some stored data
An input method for entering data
Some process that turns the data into information
An output method for representing information
May also have:
Subsystems that we can also regard as systems
Interfaces with other systems
© 2010 Bennett, McRobb and Farmer

11. System Transformation
All useful systems transform their inputs into useful outputs
For IS, inputs are typically data or information and outputs are typically also information
This transformation is the whole reason for building and operating the system
It must render the input data useful in some new way
That all useful systems produce useful outputs is clearly a tautology, but still an important point.
It is worth spending a little time on getting the class to identify useful transformations for some example systems, and discuss how these are related to wider goals.
© 2010 Bennett, McRobb and Farmer

12. Transformation Example
McGregor’s Delivery Scheduling System may have inputs:
Information about orders, available stock, customer addresses, vehicle capacities…
…And may have outputs:
Which orders to load on each vehicle, what route the vehicle should follow…
How does this benefit McGregor?
To pick up an earlier point, you could ask the class if this system must necessarily be automated. If it is, what are the likely costs and benefits?
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Are Systems Real?
Maybe, maybe not!
Systems thinking is useful because it helps to analyse and understand problems
What matters is the understanding you achieve
You can choose to see anything as a system, whether or not it really is one
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14. Systems and the Real World
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15. Systems and Subsystems
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Types of IS
Information Systems are used to support people’s activities
Store and retrieve information
Carry out calculations
Aid communication
Control and schedule work
Other support …. ?
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Types of IS (cont’d)
Operational Systems assist or control business operations
An Accounting System replaces costly and error-prone human clerks
Management Support Systems help managers to decide or to communicate
A Delivery Scheduling System helps decide how to load and route the delivery trucks
This slide could be used to pick up some ethical aspects of automation, especially the possible effects on individuals and communities when jobs are automated. I would not, however, recommend the over-simplification that displacing jobs is always a bad thing. There is little evidence that IT has reduced employment overall. Rather, it has restructured the employment market, replaced some jobs with others, and changed the nature of others (some for better and others for worse).
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Types of IS (cont’d)
Real-time Control Systems typically operate physical equipment, often in safety-critical settings
Some cars have an Engine Management System to control fuel supply and ignition
© 2010 Bennett, McRobb and Farmer

19. How Do IS Relate to the Human Activity System?
We can view an organization as a system, perhaps with many subsystems
Ideally, each subsystem helps the overall system fulfil its purpose
IS are also subsystems and should help to meet goals of people in the organization
© 2010 Bennett, McRobb and Farmer

20. Strategy and Planning for IS
Value Chain analysis is one popular way to analyse an organisation:
Managers can focus on IS that help each of the critical activities along the ‘chain’
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21. Multiple Strategies for IS and IT
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Summary
In this lecture you have learned about:
What an information system is
Some examples and types of IS
Basic concepts of systems theory, and how to apply them to understanding IS
How IS are related to organizations
© 2010 Bennett, McRobb and Farmer

23. © 2010 Bennett, McRobb and Farmer
References
Bennett, McRobb and Farmer (2010)
Checkland and Holwell (1998)
(For further bibliographic details, see Bennett, McRobb and Farmer)
© 2010 Bennett, McRobb and Farmer