Final answer:
Checking boxes at the Walmart warehouse for accuracy against the shipping statement is an example of screening operational control, designed to correct deviations during the process.
Step-by-step explanation:
The practice of checking boxes at a Walmart warehouse to ensure they contain the items listed on the shipping statement is a form of operational control called screening. Screening control, also known as concurrent control, involves the review of ongoing activities to ensure that they are being conducted as planned and to correct any significant deviations. An example of screening control could be inspecting items on an assembly line or, as in this case, ensuring the accuracy of orders before they are shipped.