An ABC trading investment company wants to build a connection system between buyers and parties sell essential items. In the context of complicated epidemic developments, users have demand for essential products such as meat, fish, vegetables, tubers, etc. These foods offered by reputable suppliers in the market. ABC Company is an investor in a software system to manage these services provide the best service for buyers and sellers, companies that want to build and manage a system The system provides services such as sales registration, purchase registration, delivery, and other services other service. The company will collect fees based on the number of invoices generated, the main revenue of the company will come from this main activity. The next chalk will describe the processes in the project.