The Adtran case study showcases how the company has successfully integrated sales, marketing, engineering, and new product design for consensus planning. The business has shifted to more digital and flexible methods, moving away from traditional manual processes. The study also highlights the importance of demand planning and the challenges associated with it in the context of supply chain excellence. The case study explores the concepts of S&OP and its evolution at Adtran, and how similar challenges are faced by other companies such as Bell Helicopter. The article also discusses the significance of these concepts in general and the potential problems that may arise.