1. The systems approach
Churchman, C.W. (1968) The Systems Approach, Dell Publishing Co., New York.
Ackoff, R.L. (1971) Towards a system of system concepts. Management Science, Vol. 17, No. 11, P
Von Bertalanffy L. (1968) General Systems Theory: Foundations, Development, Applications, Penguin, London.

2. Definition of the system
A system is an assembly of parts or components existing together in an organised way
The assembly is of particular human interest
Parts are affected by being in the system - they change if they leave
The assembly does something - it has an aim
Open University definition

3. Types of systems (Checkland, 1981)
Natural systems
Designed physical systems
Designed abstract systems
Human activity systems
INFORMATION SYSTEMS

4. Types of model Descriptive models Predictive models
Normative or optimising models
Descriptive models

5. The systems approach Main concepts and assumptions
basic concepts
described in terms of input, output, process, boundary, environment
input and output - static objects transformed by dynamic processes
control system is essential for unpredictable systems
The state space approach - views processes (update processes) as transformations between one state to another. A state at a given instant consists of the objects in the system at that instant.

6. Types of activities and information
MANAGEMENT
ACTIVITIES
FUNCTIONAL ACTIVITIES

7. Types of activities and information (EXAMPLES)
functional activities
processing a shipment order
paying employee wages
processing sales
...
management activities
scheduling jobs
hiring and firing staff
managing departmental budgets
checking organisational performance against objectives
deciding on new markets or strategies

8. E E FUNCTIONAL SYSTEM Process Input Output Standard Sensor Activating
unit
Control
device
CONTROL SYSTEM

9. FUNCTIONAL SYSTEM
CONTROL SYSTEM
Design

10. Applying the systems approach
FUNCTIONAL SYSTEM
CONTROL SYSTEM
Information
system
Management system
Changes

11. Information Changes Information Management system Event Information
FUNCTIONAL SYSTEM
Event
Information
Input system
Information
base
HCS
Simulation
system
Message
system
Changes
Information
system
Output system
Information
Management system
CONTROL SYSTEM

12. Interaction of functional and control systems
1. The event occurs in the functional system
2. The human computer system (input system) records details concerned with the functional system event
3. The input system initiates appropriate simulation system process
4. The simulation system process updates the information base
5. The user initiates the human computer system (output system) process to start the appropriate message system process to obtain information from information base
6. The user performs the management system activity using the information obtained
7. Possible changes are made to the functional system

13. Management system components
Information
system
Internal users
External users
Informational
Decision making
Interpersonal
Management system

14. Applying the systems approach OMNIS model an Overview Model of aN Information System in its organisational context
Functional system
Static
component
Dynamic
Input/output
Object
Property
Rule
Behaviour
Event
Process

15. OMNIS model Control system Information system Management system
Simulation
system
Message
system
Human computer
system
Input
system
Output
system
Rule
base
Information
base
Process
Data
capture
Transact.
input
Query
Report
Rule
Object
Property
Event

16. OMNIS model ORGANISATION Functional system Control system Static
component
Dynamic
component
Information
system
Management
system
Input/output
Rule
Behaviour
Simulation
system
Message
system
Human computer
system
Object
Property
Event
Process
Rule
base
Information
base
Process
Input
system
Output
system
Rule
Object
Property
Data
capture
Transact.
input
Query
Report
Event

17. OMNIS Principles Non-redundancy - model fact only once
Completeness - model all the relevant facts
Accuracy - do not invent facts (model only what is in the description)
Clarity
model fact as an object rather than a property
only model important properties

18. The systems approach Advantages and disadvantages
description of system using intuitively familiar notions (input, output, process)
decomposition
notion of control system
description suitable for communication
Disadvantages
possibility of non-unique descriptions
there is no guidance concerning level of detail (possibility of incompleteness of description)
no method is suggested to apply approach