In a comparison between P systems and Q systems, what should be higher in P systems?

In P systems, which refer to periodic review inventory systems, it is expected that safety stock will be higher compared to Q systems, which represent continuous review systems. The reasoning behind this lies in the fundamental operational characteristics of each system.

P systems operate on fixed review periods, meaning inventory levels are assessed and ordered at predetermined intervals. This can lead to greater uncertainty regarding the actual demand during the period before the next review. To mitigate the risk of stockouts across this longer period without an actual inventory check, it is necessary to hold higher levels of safety stock.

On the other hand, Q systems allow for continuous monitoring of inventory levels, and replenishment orders are triggered as soon as inventory falls to a predetermined reorder point. This allows for a more responsive approach to variations in demand, which can often result in lower safety stock levels compared to P systems, as the system can react more frequently to changes in demand.

Thus, because of the periodic nature of inventory checks in P systems and the associated uncertainties, holding a higher amount of safety stock is essential to ensure service levels can be maintained.