System development life cycle (SDLC)

A typical SDLC moves through several phases. Planning establishes the business case, scope, and feasibility. Analysis gathers and documents user requirements for what the system must do. Design translates those requirements into technical specifications for data structures, interfaces, and processes. Development builds or configures the software, testing verifies it against the requirements through unit, integration, and user acceptance testing, and implementation puts it into production. Maintenance then covers ongoing fixes, enhancements, and a post-implementation review comparing actual results to the original business case.

Conversion strategy is a decision point at implementation. A parallel conversion runs the old and new systems together and reconciles results — the safest option and the most expensive. A direct cutover switches everything at once, which is cheapest and riskiest. Pilot conversion deploys to one location or group first, and phased conversion brings modules live in stages. Development methodology also varies: the traditional waterfall model completes each phase before the next begins, while agile approaches deliver working increments in short iterations with continuous user feedback.

For accountants and auditors, the SDLC is primarily a control framework. Requirements should be authorized and documented so the finished system can be traced back to them; developers should not have access to production data or the ability to migrate their own code; changes should pass through formal change management with testing evidence retained. Segregation of duties between development, testing, and operations is the central general control, and involving internal audit early is cheaper than remediating a deployed system.

The CMA Part 1 exam tests the SDLC in two places: technology-enabled finance transformation, where you need the phases and their deliverables, and internal control, where system development controls appear alongside other general information technology controls. Know the phase order, the conversion approaches, and which controls belong to which phase.