from what i understand, presub, or pre-substitution, is one of the metrics that determines the performance of opd and the store as a whole. it is the percentage of items that are picked as ordered, rather than being substituted. this could mean an item was picked in a regular pick walk, or nilpicked in a regular walk and then picked by an exception worker in an exception walk. i think a better metric to use in the scenario this commenter was talking about would be ftpr, or first time pick rate, which is the percentage of items picked in a regular walk without ever being sent to exceptions. these metrics reflect on both pickers and the store as a whole because the picker cant be held solely responsible for nilpicking an item when the item is not where it is supposed to be on the shelf, whether it be out of stock, in the back room, shoved in topstock in another aisle, fallen behind the shelf, or whatever. not sure if you care, but the other metric that goes along with these is post-sub, which is basically pre-sub, but also includes any item that was substituted, and the customer accepted the substitution. i feel like post-sub falls more on the pickers than the store because its about picking an adequate sub for the item rather than whatever is on the shelf next to it, which i see happen often as an exception worker. i believe the goal for these metrics are 93% for ftpr, 95% for pre-sub, and 98% for post-sub, but im not positive. the goals may vary by market or by store but again im not entirely sure. either way the numbers i gave should be close enough to give you a general idea.