Introduction
Creating a study plan for the Statistics Optional subject is crucial for effective and organized preparation. It helps in managing time, covering all the topics, and ensuring thorough understanding of the subject. The ideal time to start creating a study plan depends on several factors.

Considerations for Creating a Study Plan
Before determining the ideal time to start creating a study plan, it is important to consider the following factors:

1. Exam Date: Take into account the date of the UPSC examination. This will help in allocating sufficient time for each topic and revision.

2. Prior Knowledge: Evaluate your existing knowledge and understanding of statistics. If you have a strong foundation, you may require less time for preparation compared to someone with little or no prior knowledge.

3. Available Time: Assess the amount of time you can dedicate to studying each day. This will help in creating a realistic and achievable study plan.

Ideal Time to Start Creating a Study Plan
Considering the above factors, the ideal time to start creating a study plan for the Statistics Optional subject is approximately 8-10 months before the UPSC examination. This provides ample time to cover all the topics in depth, revise multiple times, and practice solving questions.

Study Plan Creation Process
To create an effective study plan, follow these steps:

1. Syllabus Analysis: Carefully go through the UPSC syllabus for the Statistics Optional subject. Divide it into broad topics and subtopics.

2. Time Allocation: Estimate the amount of time required to cover each topic based on its complexity and your prior knowledge. Allocate more time to difficult topics and less time to familiar ones.

3. Weekly and Monthly Targets: Break down the syllabus into weekly and monthly targets. Assign specific topics to each week and month, ensuring comprehensive coverage of the subject.

4. Revision Strategy: Plan regular revision sessions at fixed intervals. Allocate sufficient time for revisiting previously covered topics to reinforce understanding and retention.

5. Practice Questions: Allocate time for solving practice questions and previous year papers. This will help in familiarizing yourself with the exam pattern and increase speed and accuracy.

6. Mock Tests: Include regular mock tests in your study plan to assess your progress and identify areas that need improvement. Analyze your performance and work on weak areas.

7. Flexibility: Keep your study plan flexible to accommodate unforeseen circumstances or delays. Don't panic if you fall behind schedule; instead, adjust your plan accordingly.

Conclusion
In conclusion, starting your study plan for the Statistics Optional subject approximately 8-10 months before the UPSC examination is ideal. This allows sufficient time for comprehensive coverage of the syllabus, revision, practice, and mock tests. Remember to analyze your strengths and weaknesses, allocate time wisely, and stay committed to your study plan to achieve success in the UPSC examination.