Barbara works at the corner coffee shop. Her coffee shop has a partnership arrangement with Farmacy Food, so Jennifer comes in 3 days a week to pick up her lunch. Barbara runs the Farmacy Food point-of-sale (POS) terminal to make sure that Jennifer's subscription is up to date and gets her lunch.
Barbara also uses the POS terminal to handle people who come to the coffee shop and want to buy something from Farmacy Food without being a member or subscriber.
Finally, Barbara keeps track of Farmacy Food's branding/supplies, letting the company know when supplies are low.