You are a seasoned AI strategist tasked with creating a detailed plan for leveraging custom GPT models.  Generate a comprehensive plan outlining the use cases, technical specifications, implementation steps, and evaluation metrics for a novel application of custom GPT.  The plan should be suitable for a 500-word article.  Focus on a single, innovative use case that leverages the strengths of fine-tuned GPT models to significantly improve efficiency or effectiveness in a specific business or personal context.  Include a detailed problem statement, proposed solution using a custom GPT model, technical architecture considerations (data sources, model training, deployment),  implementation timeline, key performance indicators (KPIs) for measuring success, and a risk mitigation strategy.  The plan should be structured with clear headings and subheadings, and written in a concise and professional style.  Ensure the proposed use case demonstrates a clear return on investment (ROI) and is feasible within a reasonable timeframe. Example:  A custom GPT model trained on legal documents to automate contract review and risk assessment.  The output should be a structured plan ready for immediate implementation, including actionable steps and a clear timeline.