To develop an internal audit plan that aligns with ISO 9001 standards, focusing on the most critical areas for compliance, follow these steps:

1. **Conduct a GAP Analysis**: Determine the extent to which your organization already complies with ISO 9001:2015. This will help identify areas that need attention.

2. **Establish a Project Plan**: Define activities, deadlines, and other relevant information needed to address the gaps identified in the GAP analysis.

3. **Plan the Audit Schedule**: Develop a schedule that outlines when each part of the audit will take place, ensuring all areas of the QMS are covered.

4. **Plan the Process Audit**: Identify the processes that are most critical to your organization and have the highest probability of nonconformities. Focus on these areas during the audit.

5. **Conduct the Audit**: Execute the audit according to the plan, ensuring that all requirements of the standard are covered. Pay special attention to complex processes.

6. **Report on the Audit**: Document the findings of the audit, including any nonconformities and areas for improvement.

7. **Follow-up on Issues or Improvements Found**: Implement corrective actions for any nonconformities and track improvements.

8. **Conduct a Management Review**: Review the audit findings with management to ensure that the QMS is effectively implemented and maintained.

By following these steps, you can ensure that your internal audit plan is comprehensive and aligned with ISO 9001 standards.