A marketing plan has three phases: planning, implementation, and control. It is composed of an analysis of the current situation, objectives and strategy, and financial projections. The planning phase involves defining objectives, conducting a SWOT analysis to identify opportunities, and determining segmentation, targeting, and positioning. The implementation phase uses the marketing mix of product, price, place, and promotion. The control phase evaluates performance using marketing metrics. An effective marketing plan follows this process to organize efforts for business success.