Which of the following is the first phase in the Software Development Life Cycle?

• A. Requirements
• B. Design
• C. Implementation
• D. Maintenance

Answer: (A)

The first phase is about capturing and defining what the system should do. In this initial step you gather input from stakeholders, users, and constraints to articulate the functional requirements (the features and behaviors the system must have) and nonfunctional requirements (attributes like performance, reliability, security, and usability). This requirements specification serves as the contract and guide for everyone on the project, so designers know what to build, developers know what to implement, and testers know what to verify.

Why this ordering matters: you can’t design or implement a system effectively without a clear understanding of the problem to solve and the features needed. If requirements aren’t well defined first, you risk building the wrong thing, missing critical capabilities, or overreaching scope, which leads to costly rework later. After this foundation, the team proceeds to design a solution that satisfies those requirements, then implements it, tests it, deploys it, and finally maintains it.