This lesson explains the structured process that professionals use to plan, build, and maintain a new information system, like a library management system for a school.

Short Notes

• System: A collection of components (input, process, output) that work together to achieve a goal.

• Information System: A system that turns raw data into useful information. It can be Manual (using paper files) or Computer-Based.

• System Development Life Cycle (SDLC): The step-by-step process for developing an information system.

The 6 Phases of the SDLC:

1. Identification of Requirements: Understanding the problem and what the new system needs to do. Information is gathered through methods like observation, interviews, and questionnaires.

2. Designing the Solution: Planning how the system will work. This includes designing the user interface, database, and overall architecture.

3. Coding of the Solution: Writing the program code using a programming language.

4. Testing and Debugging: Finding and fixing errors (bugs) in the system. This includes Unit Testing (testing small parts) and System Testing (testing the whole system).

5. Deployment of the System: Installing and launching the new system. There are four main ways to do this:

• Direct: The old system is shut down and the new one starts immediately. (Risky)

• Parallel: Both the old and new systems run at the same time for a while. (Safe but expensive)

• Pilot: The new system is launched in only one department or location first.

• Phased: The new system is introduced one part at a time.

1. Maintenance of the System: Making updates, fixing problems, and improving the system after it has been launched.

Important Points for the Exam

• Memorize the 6 phases of the SDLC in the correct order. This is a very common exam question.

• Be able to briefly describe what happens in each phase.

• You must know the four deployment methods (Direct, Parallel, Pilot, Phased) and be able to explain the advantages and disadvantages of each.

• Remember the difference between a Manual System and a Computer-Based Information System.

Tips & Tricks for Studying

• Use a Mnemonic: Create a sentence to remember the 6 phases. For example: "I Don't Cook Tasty Dishes Much" (Identification, Design, Coding, Testing, Deployment, Maintenance).

• Think of a Real-World Example: Imagine your school wants a new computer system to track student attendance. Apply the 6 SDLC phases to this project. What would you do in the 'Identification' phase? How would you 'Deploy' it?

• Focus on the "Why": For deployment methods, don't just memorize the names. Understand why an organization would choose one over another (e.g., a bank would likely use a Parallel or Phased deployment because a Direct deployment is too risky with financial data).