Diagram

First Level Diagram (Context Diagram)
(Process 0)


The diagram above shows the recommended system for the Chilyn’s Pharmacy and Convenience store. The mainenvironment is the Basic Point of Sale System. It has considered three main entities which are as follows; customer, inventory system and the cashier-computer entity.The customer’s purchased goods serve as an input for the system for it to be able to get the total cost of the goods purchased by the customer. As this isbeing done, the inventory system checks the availability of the similar good that has been purchased for it to keep track the entity’s remaining inventory. Because ofthis, the sales recorded by the system will serve as the input for the inventory system entity for it to be able to check its availability.

The cashier-computerentity functions as the entity performing the so-called scanning of the goods purchased to a bar-code reader together with the computer. The cashier swipes the goodsto the bar-code reader then the system will recognize the product’s code. The price of each item being swiped will then be displayed to the computer. The system willalso create a list of the different goods purchased together with its quantity and price. When all goods have passed on the bar-code reader the system will tally thegoods and will be able to have the total cost of the goods purchased, the total quantity of the goods and other details such as the name of the cahier, time and date ofissuance of receipt and the like. A receipt then will be made available which will be an output of the cashier-computer entity to be received by the customer entity.