Flexibility is the ability of a process or system to adapt to changes in customer demand, product mix, or production volume. A flexible process can respond quickly and efficiently to these changes, minimizing disruptions and costs. One of the key measurements of flexibility is machine changeover time, which is the time required to switch a machine or equipment from producing one type of product to another. A shorter machine changeover time means a higher level of flexibility, as the process can accommodate different products or orders without wasting time or resources. This aligns with CPIM's focus on plan, manage, and execute detailed schedules and manage quality, continuous improvement, and technology. References: The concepts are covered in detail in Module 5: Detailed Scheduling and Planning (1 and Module 6: Quality, Continuous Improvement, and Technology (2. You can also find more information about flexibility and machine changeover time from these sources: 3, 4, and 5.

The correct answer is C. Inventory items .
ABC analysis classifies inventory items according to relative importance, most commonly by annual usage value. In the typical ABC pattern, "A" items represent a small percentage of the total number of items but a large percentage of total inventory value or annual usage value. Therefore, "A" items generally represent about 20% of the inventory items , not 20% of the value.
Exact extract: "Items can be ranked in order of their relative importance by ABC analysis... This technique ranks items as A- B- or C-class most commonly according to their annual usage value. Inventory management may then focus most on A-class and least on C-class items." The practice material also explains the control logic: "ABC inventory control operates on the assumption that a company should allocate its limited resources to maintaining high priority items or 'A' items." Therefore, "A" items generally represent about 20% of the inventory items , while accounting for a much larger share of annual usage value.

To minimize the total time, eliminating setup time provides the greatest impact. The setup time (2 hours) is a fixed time block, and eliminating it immediately reduces the total time needed, while changes in efficiency or processing time yield more gradual improvements.
"Required time = Setup time + (Processing time × Batch size) / (Utilization × Efficiency)"
- CPIM ECO/MRP Study Notes, CPIM-400PQ calculations