Chapter 4: Value-Based Systems: Activity-Based Costing and Lean Accountin Comparison of ABM and Lean Operations E15A. BUSINESS APPLICATION about their companies' management systems follow. Identi Excerpts from a conversation between two managers fy the manager who works for a company that emphasizes ABM and the one who works for a company that empha- sizes a lean operating system. Manager 1: We try to manage our resources effectively by monitoring operating activities. We analyze all major operating activities, and we focus on reducing or eliminating the ones that don't add value to our products. Manager 2: We're very concerned with eliminating waste. We've designed our operations to reduce the time it takes to move, store, queue, and inspect materials. We've also reduced our inventories by buying and using materials only when we need them