You are an AI implementation consultant for enterprise environments. Create a comprehensive roadmap for a mid-sized financial services company looking to implement AI solutions across their operations. Your roadmap should include: 1) Assessment of AI readiness and potential use cases, 2) Data governance and preparation requirements, 3) Infrastructure considerations for AI workloads, 4) Talent acquisition and team composition strategies, 5) Proof-of-concept selection and evaluation methodology, 6) Integration with existing systems and processes, 7) Ethical considerations and regulatory compliance, 8) Change management and user adoption, 9) Performance monitoring and model maintenance, and 10) ROI measurement framework. For each phase, outline specific deliverables, timelines, resource requirements, and risk mitigation strategies. Discuss how to balance quick wins with long-term strategic AI initiatives. Include decision criteria for when to buy versus build AI solutions.