Final answer:
The Master Production Schedule (MPS) is the MRP system input that specifies the quantity and timing for the production of end items. It's crucial in aligning production with business plans and customer demand.
Step-by-step explanation:
The input element of the MRP system that specifies how many, and when, the firm plans to produce each end inventory item is b. Master Production Schedule (MPS). The MPS is a detailed plan that states which end items are to be produced, in addition to the quantity and the timing of each. It serves as a key input into the Material Requirements Planning (MRP) system, aligning the production schedule with the overall business plan and market demand, thereby ensuring that inventory levels are maintained at optimal levels to fulfill customer orders without excess stock. The Bill of Materials (BOM) lists the raw materials, components, and assemblies needed to produce an end item, the Inventory Status Report (ISR) provides current inventory levels, and the Material Requirements Planning (MRP) itself is a system for calculating the materials and components needed to manufacture a product.