The System Development Life Cycle (SDLC) is a fundamental framework used in information technology to plan, create, test, and deploy an information system. It provides a structured approach to developing high-quality systems that meet or exceed customer expectations, work within cost and time estimates, and are effective and efficient. For CPA candidates, understanding SDLC is crucial as it underpins the development and management of financial information systems, audit trails, and internal controls.

The SDLC is typically divided into several distinct phases. While the exact number and names of phases can vary slightly between methodologies, the core concepts remain consistent. We will explore the most common phases.

This initial phase involves understanding the problem or opportunity, defining the scope of the project, and gathering detailed requirements from stakeholders. Feasibility studies (technical, economic, operational) are conducted to determine if the project is viable. The output is a detailed project plan and a requirements specification document.

In this phase, the system architecture and design specifications are created based on the requirements gathered. This includes defining the overall structure, modules, interfaces, and data structures. Design can be divided into high-level design (architectural) and low-level design (detailed module design).

This is where the actual coding takes place. Developers write code based on the design specifications. The system is built module by module, and these modules are integrated to form the complete system.

Once the code is written, it undergoes rigorous testing to identify and fix defects. Various types of testing are performed, including unit testing, integration testing, system testing, and user acceptance testing (UAT), to ensure the system functions as per requirements and is free of bugs.

After successful testing, the system is deployed into the production environment. This involves installing the software, configuring hardware, and migrating data. Training for end-users is also a crucial part of this phase.

This is the longest phase, where the system is in operation. It involves ongoing support, bug fixing, performance monitoring, and implementing enhancements or updates to adapt to changing business needs or technological advancements. This phase ensures the system remains functional and relevant over its lifespan.

Different methodologies exist to implement the SDLC, each with its own approach to managing the phases. Common ones include Waterfall, Agile, Spiral, and V-Model. For CPA exams, understanding the core principles of SDLC is more important than memorizing every detail of each methodology, but awareness of their existence and general characteristics is beneficial.

Understanding SDLC is vital for CPAs as they often audit financial systems, assess internal controls over information technology, and advise on system implementations. Knowledge of SDLC helps in evaluating the adequacy of controls at each stage of system development, ensuring data integrity, security, and compliance with regulations. Questions on CPA exams may relate to identifying risks at different SDLC phases, understanding the purpose of specific testing types, or evaluating the impact of SDLC on internal controls.