What is more important in an AI project: the model, data, tools, or business requirement?

A successful AI project needs all four, but the business requirement should provide the direction for the solution. A powerful model cannot compensate for unclear objectives, poor-quality data, inappropriate tools, or an undefined success criterion. The business requirement should determine what the agent needs to know, which tools it should access, what the model needs to accomplish, and how success will be measured. Students and professionals should therefore think beyond model selection and consider architecture, data quality, security, integration, and governance. Which of these four would you prioritize when designing an enterprise AI solution, and what would you evaluate first?