Inventory on hand:
Inventory on hand refers to the quantity of materials or products that a company currently has in its possession. This information is necessary for material requirements planning (MRP) because it helps determine if there is enough inventory available to meet production demands. If the inventory on hand is insufficient, the MRP system can generate purchase orders or production orders to ensure that enough materials are available.

Bill of materials:
The bill of materials (BOM) is a detailed list of all the components and raw materials required to produce a finished product. It includes information such as part numbers, quantities, and descriptions. The BOM is a critical input to MRP because it provides the necessary information to calculate the requirements for each component based on the production schedule. Without a BOM, the MRP system would not be able to accurately determine the quantity of each component needed for production.

Master production schedule (MPS):
The master production schedule (MPS) is a plan that specifies the quantity and timing of finished products to be produced. It takes into account factors such as customer demand, production capacity, and inventory levels. The MPS is an essential input to MRP because it provides the information needed to determine the quantity and timing of component requirements. Without an MPS, the MRP system would not be able to generate accurate production orders or purchase orders.

Sequence of operations on a job:
The sequence of operations on a job refers to the specific order in which the manufacturing processes need to be performed to produce a finished product. This information is typically included in the routing or process sheet for each job. While the sequence of operations is important for production planning and scheduling, it is not a necessary input to MRP. MRP focuses on determining the material requirements based on the production schedule, inventory levels, and BOM. The sequence of operations is more relevant to shop floor control and scheduling activities.

Therefore, the correct answer is option C - Sequence of operations on a job. This information is not a necessary input to MRP.