Once you have defined your audit objectives, you need to collect and analyze data from various sources to assess your suppliers' performance and identify cost savings opportunities. This data can come from supplier invoices, purchase orders, delivery notes, quality reports, certificates, feedback, contracts, agreements, SLAs, self-assessments, surveys, and audits. Additionally, internal data such as inventory levels, lead times, defect rates, and customer satisfaction can be used. To analyze the data effectively you can use benchmarking to compare your suppliers' performance with industry best practices or your own standards. Spend analysis is another useful tool for identifying spending patterns and trends across suppliers. Cost breakdown analysis can be used to break down the components of your suppliers' prices and identify the drivers of cost. Lastly, value analysis can be used to evaluate the value-added and non-value-added activities of your suppliers and eliminate waste and inefficiencies.