In the context of ABC inventory analysis, which of the following statements is true of class A items? a. They can be managed using automated computer systems. b. They comprise less than 30 percent of the total dollar usage. c. They account for more than 50 percent of inventory items. d. They require close control by operations managers.

Asupermarket has been experiencing long lines during peak periods of the day. the problem is noticeably worse on certain days of the week, and the peak periods are sometimes different according to the day of the week. there are usually enough workers on the job to open all cash registers. the problem is knowing when to call some of the workers stocking shelves up to the front to work the checkout counters. how might decision models the supermarket? what data would be needed to develop these models?