Definition of Software Development Life Cycle (SDLC) Software development is a complex process that requires careful planning, execution, and maintenance. The Software Development Life Cycle (SDLC) is a methodology that outlines the stages of software development, from planning and requirements gathering to deployment and maintenance. This approach ensures that software is developed and released with high quality and meets user requirements. SDLC is a systematic process that divides software development into various stages, each with its own objectives and deliverables. This process includes planning, design, development, testing, deployment, and maintenance. It aims to create software that meets the user's requirements, is of high quality, and can be maintained efficiently. Phases of SDLC The SDLC process is divided into several phases, each with its own objectives, activities, and deliverables. The following are the six phases of the SDLC: Planning and Requirements Gathering This phase involves identifying the software requirements and creating a plan to meet those requirements. It includes defining the project scope, creating a budget, and identifying project risks. Design This phase involves creating a design for the software based on the requirements gathered in the previous phase. It includes creating a functional specification document, designing the user interface, and creating a database schema. Development This phase involves coding the software based on the design specifications. It includes creating the software modules, integrating the modules, and testing the software code. Testing This phase involves testing the software to ensure that it meets the requirements and is free of defects. It includes unit testing, integration testing, system testing, and user acceptance testing. Deployment This phase involves deploying the software to the production environment. It includes installing the software, configuring it, and training end-users. Maintenance This phase involves maintaining the software to ensure that it continues to meet the user's requirements. It includes fixing defects, adding new features, and making modifications based on user feedback. Models of SDLC There are several models of SDLC that software development teams can use. The following are the three most common models: Waterfall Model The waterfall model is a linear approach to software development that involves completing each phase before moving on to the next. It is a traditional approach that is best suited for projects with well-defined requirements. Agile Model The Agile model is an iterative approach to software development that involves breaking down the project into small, manageable tasks. It is best suited for projects with changing requirements and tight timelines. Spiral Model The spiral model is a flexible approach to software development that combines elements of the waterfall and Agile models. It involves repeating cycles of planning, design, development, and testing. Advantages and Disadvantages of SDLC The SDLC process has several advantages and disadvantages: Advantages • Ensures that the software meets the user's requirements. • Ensures that the software is of high quality. • Ensures that the software can be maintained efficiently. • Provides a structured approach to software development. Disadvantages • Can be time-consuming. • Can be expensive. • Can be inflexible.