Final answer:
The ideal lot size in the JIT philosophy is one unit, reflecting its goal to minimize inventory and improve efficiency by aligning production or procurement closely with immediate demand.
Step-by-step explanation:
In the JIT philosophy, the ideal lot size is considered to be option C. one unit. This approach to inventory management is premised on the idea of reducing waste and improving efficiency by producing or ordering goods as close as possible to when they are actually needed. Unlike the traditional Economic Order Quantity (EOQ) model, which seeks to optimize the cost associated with ordering and holding inventory, JIT aims to minimize inventory levels to near-zero whenever possible. The concept of one unit as the ideal lot size refers to the production or procurement of single items at a time in alignment with immediate demand, ensuring operational agility and reducing holding costs.