System Development Life Cycle — Council for the Curriculum, Examinations and Assessment Other General Qualification Digital Skills & IT Revision
This subtopic explores the structured process of developing information systems through the System Development Life Cycle (SDLC), covering phases from init
Topic Synopsis
This subtopic explores the structured process of developing information systems through the System Development Life Cycle (SDLC), covering phases from initial planning to maintenance. It examines the critical role of feasibility studies in assessing project viability and contrasts traditional sequential approaches like Waterfall with iterative methodologies such as Agile, emphasising their practical implications for project success and resource management in real-world IT contexts.
Key Concepts & Core Principles
- Types of Information Systems: Understand the differences between TPS, MIS, DSS, and EIS, including their purpose, users, and outputs. For example, TPS handles routine transactions like payroll, while DSS supports semi-structured decisions using models and data.
- System Development Life Cycle (SDLC): Know the stages (planning, analysis, design, implementation, testing, maintenance) and methodologies like Waterfall and Agile. Be able to evaluate which approach suits different scenarios.
- Data vs. Information: Data is raw facts; information is data processed to be meaningful and useful for decision-making. Understand the attributes of good information (accurate, timely, relevant, complete, etc.).
- Stakeholders and Their Roles: Identify internal and external stakeholders (e.g., users, managers, IT staff, customers) and how their needs influence system design and success.
- Ethical and Legal Issues: Data protection (GDPR), intellectual property, computer misuse, and professional codes of conduct. Know how these affect the collection, storage, and use of information.
Exam Tips & Revision Strategies
- Use the exact SDLC terminology from the specification (e.g., 'feasibility study' rather than 'initial check') to demonstrate precision.
- In extended response questions, adopt a direct comparative structure (e.g., a table or clearly signposted paragraphs) to ensure both methodologies are equally evaluated.
- Always link feasibility studies to the business case, explaining how each type of feasibility influences the decision to proceed with the project.
Common Misconceptions & Mistakes to Avoid
- Confusing the order of SDLC stages, such as placing implementation before design or omitting maintenance as a distinct phase.
- Assuming feasibility studies only consider financial costs, neglecting technical, operational, or legal constraints.
- Describing Agile as having no planning or documentation, rather than recognising its iterative planning and lightweight documentation.
- Failing to provide concrete examples when comparing methodologies, leading to vague or unsupported statements.
Examiner Marking Points
- Award credit for accurately listing and sequencing the key stages of the SDLC (e.g., planning, analysis, design, implementation, testing, maintenance) and describing the core activities within each.
- Credit should be given for clearly defining feasibility studies and distinguishing between types (technical, economic, operational, legal, schedule) with relevant examples that inform go/no-go decisions.
- When comparing Waterfall and Agile, examiners expect explicit contrast in terms of flexibility, customer involvement, risk handling, and suitability for different project types, supported by real-world scenarios.