What is an information system?
An information system (IS) is an organised set of parts that collects, stores, processes and shares information to help people work and decide.
It does not have to be digital (a library card index is an IS), but today most use computers. Its six components are:
- People: users and the staff who run it.
- Hardware: computers, phones, servers, scanners.
- Software: programs and apps.
- Data: the raw facts stored, usually in a database.
- Network: the links that carry data (internet, Wi-Fi).
- Procedures: the rules and steps for using the system.
Its main functions: input, processing, storage, output and feedback (checking results to correct the system).
Data, information and knowledge
Data are raw facts with no context: 72, 85, 64.
Information is data that has been organised and given meaning: "Asha's average maths score is 74 %".
Knowledge is using information to understand and act: "Asha should practise algebra before the exam".
Organisations treat information as a resource, like money or machines. Good information is accurate, up to date, complete, relevant and delivered to the right person at the right time.
The information chain
In a product or an organisation, information follows a chain:
- Capture (acquire): a sensor, keyboard or form collects data.
- Encode: the data is turned into a digital form (binary numbers).
- Send (transmit): a wire, Wi-Fi or mobile network carries it.
- Store: it is saved in memory or a database.
- Process: software sorts, calculates and analyses it.
- Present (output): a screen, printout, sound or motor gives the result to a person or machine.
Example: a smart thermostat measures temperature (capture), converts it to numbers (encode), sends it over Wi-Fi, stores it, decides to switch the heater on (process) and shows the reading in an app (present).
Types of information systems
- Transaction processing system (TPS): records daily events such as sales, bookings or payments.
- Management information system (MIS): turns TPS data into regular reports for managers.
- Decision support system (DSS): helps answer "what if?" questions using models and data.
- Enterprise resource planning (ERP): one shared system for the whole organisation: finance, stock, staff, production.
- Collaboration systems: shared documents, wikis and messaging that let many people work together.
How an information system is developed
Information systems are built using a system development life cycle (SDLC):
- Plan: what problem are we solving? Is it worth the cost?
- Analyse: study users and list exactly what the system must do (requirements).
- Design: plan screens, database tables, hardware and security.
- Build: write the software, set up hardware and networks.
- Test: check it works and fix errors; train users.
- Run and improve (maintain): use it, collect feedback, update it.
Many teams now work in short agile cycles, delivering a small working part every few weeks instead of everything at the end.
Strengths, limits and digital change
Strengths
- Speed and accuracy: millions of records handled in seconds.
- Sharing: many people use the same up-to-date data, so groups can build collective intelligence (shared knowledge, like a wiki or a shared project board).
- Better decisions from reports and analysis; automation of routine work.
- New ways to produce: online orders, tracking, robots and smart factories.
Limits and risks
- Cost of building, training and maintenance.
- Security and privacy: hacking, data leaks, misuse of personal data.
- Dependence: if the network or power fails, work stops.
- "Garbage in, garbage out": wrong data gives wrong information.
- Rigidity: a system can force everyone into fixed steps and be hard to change, while good digital tools can also make an organisation more agile. Which one happens depends on design and people.
Try it: map an information system near you
Choose your school library, canteen billing or a mobile recharge app. Write its 6 components (who are the people? what hardware?). Then draw the 6-step chain for one action, e.g. borrowing a book. Finally, imagine the network fails: what still works? Check your idea with the switch-off buttons in the last 3D step.
Key formulas and definitions
- Key terms: information system = people + hardware + software + data + network + procedures
- Data → (processing) → information → (understanding) → knowledge
- Functions: input, processing, storage, output, feedback
- Information chain: capture → encode → send → store → process → present
- SDLC: plan → analyse → design → build → test → run and improve
- Types: TPS, MIS, DSS, ERP, collaboration systems
Worked examples
1. Name the six components in a supermarket billing system.
People: cashier and customers. Hardware: barcode scanner, till, printer. Software: billing program. Data: prices and stock in a database. Network: link to the central server. Procedures: scan, total, take payment, print receipt.
2. Classify: (a) 37, 41, 39; (b) 'Average temperature this week was 39 °C'; (c) 'It is very hot, so the school will close at noon'.
(a) Data: raw numbers. (b) Information: data with meaning. (c) Knowledge or a decision based on information.
3. Trace the information chain when you tap a card at a metro gate.
Capture: the reader detects the card. Encode: card ID becomes digital data. Send: data goes to the server. Store: the trip is saved. Process: fare and balance are calculated. Present: the gate opens and the screen shows your balance.
4. A hospital wants a new appointment system. In which SDLC stage would it ask doctors and patients what they need?
Analyse (requirements analysis): studying users and listing exactly what the system must do.
5. Give one strength and one limit of moving school records online.
Strength: teachers and parents can see up-to-date marks anywhere. Limit: student data could leak if security is weak, and nothing works during a network outage.
Common mistakes
- Thinking an information system is only the computer. People, data, network and procedures are just as important.
- Mixing up data and information. Data are raw facts; information is processed data with meaning.
- Skipping testing or user needs when building a system. Most failed systems were built without asking users first.
- Believing a computer system is always correct. Wrong input data gives wrong output (garbage in, garbage out).