A lean relationship is a type of supplier-customer relationship that focuses on eliminating waste, improving quality, and reducing costs throughout the supply chain. A lean relationship requires a high level of collaboration, trust, and transparency between the supplier and the customer. Communication between the counterparts at the two companies is an essential activity that will enhance a successful lean relationship. Communication can help to align the goals, expectations, and performance measures of the supplier and the customer, as well as to identify and resolve any issues or problems that may arise. Communication can also facilitate information sharing, feedback, and continuous improvement initiatives. References: CPIM Exam Content Manual Version 7.0, Domain 7: Plan and Manage Distribution, Section 7.1: Develop Distribution Plans, Subsection 7.1.3: Describe how to develop supplier-customer relationships (page 66).