To measure your expansion performance accurately, you should align your metrics with your goals and scope, use a balanced and comprehensive set of performance metrics, collect and analyze reliable data, communicate and report results clearly and timely, and review and refine your performance measurement system periodically. Your metrics should reflect what you want to achieve with your expansion, covering financial, operational, customer, and social aspects. They should also be specific, measurable, achievable, relevant, and time-bound (SMART). Additionally, the data should be accurate, consistent, and relevant to your expansion. When reporting the results, they should be presented in a way that is easy to understand and actionable for your audience. Furthermore, the performance measurement system should be flexible and adaptable to changing needs and environment. Regular reviews of the metrics and benchmarks will ensure they are still valid and useful for your expansion.