Chapter 6 - Just-in-time (lean) purchasing. Just-in-time (JIT) or lean purchasing is introduced in Chapter 6. The current shift toward the so-called “Lean Thinking” manufacturing environment is one of the major motivations for JIT purchasing. JIT has changed the role of purchasing from merely placing orders to investigating the supplier’s technical and process capabilities. | Lecture Purchasing and supply chain management (3/e): Chapter 6 - W. C. Benton