Excel Workbook for Performance Analysis

I need an Excel workbook designed for data analysis, specifically for performance data. The main focus will be on analyzing operational efficiency metrics.

Requirements:
- The workbook should be user-friendly and structured to allow for easy input and analysis.
- It should include data visualization elements like charts and graphs to represent operational efficiency metrics clearly.
- The ability to handle large datasets is essential.
- Formulas and functions should be implemented for automated calculations.

Ideal skills and experience:
- Proficiency in Excel, especially with data analysis tools
- Experience in creating analytical dashboards
- Strong understanding of operational efficiency metrics
- Attention to detail and ability to deliver within budget constraints

Please provide samples of previous Excel workbooks.