Sales and operations planning (S&OP) is a process used to align supply and demand by integrating financial and operational planning. For end-of-life planning of a product family, S&OP is crucial as it helps evaluate the risk profile by considering factors like declining demand, inventory levels, and production capacity. S&OP facilitates collaboration across various departments to ensure a smooth phase-out, minimizing excess inventory and mitigating risks associated with discontinuing products.