Chapter 1 - Introduction
Information system = a set of components that collect (input), manipulate (process) and share
(output) information and provide feedback.
Information concepts
Data versus information
Data = raw facts with little value on their own.
Information = facts that have been organised (processed) into something meaningful.
The type of information created depends on the relationships defined among the data.
Process = tasks performed to achieve an outcome. (Turning data into information).
Knowledge = awareness & understanding of how to make information useful.
Information += data made useful through the application of knowledge.
Characteristics of valuable information:
Relevant - Info must be applicable.
Economical - Balance info value with production costs.
Accurate - Info without errors.
Complete - Contains all the important facts.
Timely - Info is delivered when needed.
Simple - Information that is concise and not overloaded.
Flexible - Info can be used for many purposes (by managers, sales people, etc…)
Reliable - Info can be depended on. Reliability depends on the source of information.
Verifiable - Info can be checked.
Accessible - Info should be obtained in the right format at the right time.
Secure - Info should be secure from unauthorized users.
The value of information
Measuring value: Additional profit minus the cost of the information.
System and modeling concepts
System = a set of components that interact to accomplish goals.
System components = inputs, processing mechanisms, outputs and feedback.
Knowledge is needed to define relationships among inputs and to organize elements.
System components and concepts
System boundary = the limits of the system.
The system boundary defines the system and distinguishes it from everything else, whereas
the system configuration refers to the organization of system elements.
System types:
Temporary - Exists for a short time.
Permanent - Exists for a long time.
Open - Interacts with environment.
Closed - No interaction with environment.
Adaptive - Can change in response to changes in the environment.
Nonadaptive - Can’t change in response to changes in the environment.
Dynamic - Undergoes rapid and constant change.
Stable - Undergoes little change.
Simple - Few components, with straightforward interaction.
Complex - Many elements, highly interconnected.
System performance and standards
1. Efficiency = doing things right (with minimum waste / effort).
= A measure of what is produced divided by what is consumed. (0-100%)
2. Effectiveness = doing the right thing (getting the desired result).
= A measure of the extent to which a system achieves its goals.
Divide goals actually achieved by stated goals.
System performance standard = a specific objective of the system.
E.g. The objective of baking no more than 100 loaves of bread a day.
Once standards are established, performance is measured and compared with the standard.
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System variables and parameters
System variable = something that can be controlled by the decision maker (like product price)
System parameter = something that can’t be controlled (like the cost of raw materials).
Modeling a system
Model = an abstraction used to represent reality to help you understand real-world situations.
Many contain assumptions (e.g. length of working time), which should be realistic, and users
must be aware of them.
Types of system models
1. Narrative: Verbal and written descriptions (reports, documents, conversations).
2. Physical: Tangible representation of reality (scale models, E.g. prototype of a new cinema).
3. Schematic: Graphic representation of reality (graphs, charts, diagrams, pictures).
4. Mathematical: Arithmetic representation of reality (logical models used in business).
Information systems
Input, processing, output, and feedback
1 Input = capturing raw data, manually or automatically.
2 Processing = converting data into useful outputs, manually or with computers.
3 Output = producing useful information in the form of documents or reports.
Computer output: printers and display screens.
Manual output: handwritten documents and reports.
4 Feedback = output that is used to make changes to input or processing.
Errors might make it necessary to correct input or change a process.
If output indicates low inventory levels, this feedback can be used to order more.
Reactive approach - The feedback system alerts the manager of the problem.
Proactive approach - The system predicts future events to avoid problems (= forecasting).
Manual & computerised information systems
Computerising a manual information system doesn’t guarantee improved performance,
because if it is flawed, computerising it might magnify the impact of the flaws.
Computer-Based Information Systems (CBIS)
Technology infrastructure (hardware, software, databases, telecommunications, people,
procedures) forms the foundation of each CBIS.
1 Hardware = computer equipment used to perform input, processing and output activities.
2 Software = programs that operate the computer.
3 Databases = organised collection of facts and information. (= Very valuable to a CBIS)
4 Telecommunications
Telecommunications enables organisations to carry out tasks through computer networks.
Extranet = a network that allows selected outsiders to access authorised intranet resources.
(You’re using an extranet when you track a parcel).
5 People
IS personnel = people who manage, run, program, and maintain the system
Users can also be IS personnel.
People are the most important element in most CBISs.
6 Procedures
= Strategies, policies, methods and rules for using the CBIS.
A disaster recovery plan is a procedure because it outlines what course of action to take.