IS312: information systems theory and applications LECTURE 1:SYSTEMS THEORY AND MAIN CONCEPTS Information Systems Department

Outlines 2 What is a system? Information systems definition. System Elements (Components). System Concepts Information Systems Department

Definition - Example 3 Glass Steel Rubber Plastic Copper aluminum CAR Information Systems Department

4  A system could be defined as:  “A set of interrelated components, with a clearly defined boundary, working together to achieve a common set of objectives by accepting inputs and producing outputs in an organized transformation process.”  “An organised assembly of components with special relationships between the components.” What is a System? Information Systems Department

What is a System? 5  The system does something, i.e. it exhibits a type of behavior unique to the system or has a specific objective or purpose.  Each component contributes specifically towards the behavior of the system and is affected by being in the system. If a component is removed, it will change the system behavior.  Examples: 1. The biological system of the human body. 2. The Electrical system of your house. Information Systems Department

Information systems (IS) Definition Information Systems Department 6  A combination of hardware, software, infrastructure and trained personnel organized to facilitate planning, controlling, coordinating and decision making in an organization.  A system that gathers and transforms data in order to produce information for its end_users.

Information System Resources 7 People Hardware Networks Software Data Information Systems Department

Recognizing Information Systems 8 Business professionals should be able to look at an information system and identify…  The people, hardware, software, data, and network resources they use.  The type of information products they produce.  The way they perform input, processing, output, storage, and control activities. Information Systems Department

System Elements Information Systems Department 9 INPUTSOUTPUTS BOUNDARY TRANSFORMATION PROCESS The basic elements of a system

10  Environment and Boundary  A boundary: what is inside the boundary belongs to the system, everything outside the boundary is not part of the system. Systems, or their components, inter-act with the world outside their boundary.  The system’s Environment: The part of the outside world with which the system interacts. System Elements Information Systems Department

System Elements 11  Inputs, Transformation Process and Outputs The interactions of a system with its environment can take the form of inputs or outputs.  Inputs take the form of material objects, energy and/or information flowing from the environment into the system.  Outputs are released or sent from the system back into its environment. This output can either be useful or waste.  Within the system, the inputs usually undergo some specific Transformation process at the system boundary, so that the outputs are different from the inputs.  The system components responsible for these transformations are called the Interfaces. Information Systems Department

Basic Functions of a System 12 Input Capturing and assembling elements that enter the system to be processed (Ex: raw materials, Data, students…) Capturing and assembling elements that enter the system to be processed (Ex: raw materials, Data, students…) Processing Transforma- tion process converts input into output (Ex: manufacturing process, Breathing process…) Transforma- tion process converts input into output (Ex: manufacturing process, Breathing process…) Output Transferring transformed elements to their ultimate destination (Ex: finished product, human services…) Transferring transformed elements to their ultimate destination (Ex: finished product, human services…) Information Systems Department

System Elements 13  Components and Subsystems  A system consists of various Components which, taken together, make up the system.  The interaction between the system components is responsible for processing the inputs into outputs. Although components can also interact directly with elements from the environment across the system boundary, most of their interactions will be with other components within the same system. Information Systems Department

System Elements 14  Components themselves can be viewed as smaller systems on their own: they are Subsystems of the system under consideration. The motor car, for instance, has an electrical sub-system and an air- conditioning sub-system. Information Systems Department

System Elements 15  Components and Subsystems In the case of an information system, the basic components that interact are:-  The hardware or physical equipment used to process and store data.  The software and procedures used to transform and extract information.  The data that represents the activities of the business.  The network that permits the sharing of resources between computers.  The people who develop, maintain and use the system. Information Systems Department

System Elements 16  Objectives, Control  Systems have a function, goal or purpose. This goal can be internalized  e.g. the desired room temperature for a central heating thermostat device or the profit motive in a commercial business enterprise. This goal can also be imposed from the outside  e.g. when we use a motor car to drive from our home to the shop. In order for the system to achieve its goal(s), it needs to be able to modify its behavior.  Control is the mechanism whereby special control signals or, control inputs coming from outside the system, modify the processes and activities which occur within the system. Information Systems Department

System Elements 17  Objectives, Control The Controller is the component or (sub-)system which exercises the control and can be part of or outside the system under consideration. The controller observes the behavior of the system, typically by comparing certain system outputs to the desired state or objective. Information Systems Department

Systems Concepts 18  Open vs Closed system (Greater degree with the environments vs. self sufficient (independent))  Open system : a system that interacts with its environment.  There is in reality no such thing as a closed system, which would have no inputs or outputs and therefore, in a sense, no environment.  Some systems are mainly self-sufficient while other, more open systems have a much greater degree of interaction with their environment. Information Systems Department

Systems Concepts 19  Dynamic vs Static  (the more dynamic the system  more flexibility between components  function in different ways as activities change).  A dynamic system: is a system that has at least one (and usually many) activity or process.  A static system: has no activity, whatsoever.  There are very few completely static systems. Information Systems Department

Systems Concepts 20  Continuous vs Discrete  A continuous system is a system where inputs (and outputs) can be varied by extremely small amounts or quantities.  A traffic light (robot) is a discrete traffic signaling system because its three lights (green, amber or red) are either on or off. Information Systems Department

Systems Concepts 21  Continuous vs Discrete  Discrete systems are systems where the inputs or outputs can take on only certain discrete or distinct values.  A mercury-based thermometer, is a continuous system as the level of mercury rises or falls gradually along with imperceptible fluctuations in the environment’s temperature.  Many electronic systems are a combination of both e.g. a digital thermometer has a sensor that records temperature as a continuous input but displays a temperature reading which has been rounded to the nearest degree. Information Systems Department

Systems Concepts 22  Structure and Hierarchy  The interactions between the various sub-systems and components of a system display some pattern or regularity. In this sense the observer can identify certain relationships, which contribute to the overall behavior of the system. The entire set of relationships is referred to as the structure of the system.  Structure: The physical or symbolic arrangement of the elements of a system refers to the formalized hierarchy or responsibilities and roles of the individuals therein and can also refer to the geographic distribution of inanimate elements at any given time. Information Systems Department

Systems Concepts 23  Structure and Hierarchy  System hierarchy o System within system within system o Subsystem Any component or element that belongs to a system that has a level lower than that of the system itself, for example, an organelle is a subsystem of a cell. o Suprasystem The system that has a level just higher than a given system.  e.g. physical universe (galaxies -> solar system -> planets -> Earth -> all livings -> etc.) Information Systems Department

Questions.. 24 Thank you for listening Information Systems Department

To understand faster!!! 25  Please Read Section IV: IS Management of Book(1) Discovering Information systems, Page No. from 120 to 133 for further reading. Information Systems Department

26 “A good system shortens the road to the goal.” Orison Marden