The most changing phase of the system development of life cycle is system design. It refers to the technical specification that will be applied in implementing the candidate system. The design phase is a translation from user oriented document to document oriented to programmers. The potential objects are thoroughly analyzed. Class hierarchies are to check whether the system is behaving the way it has to. There after the classes are individually tested and subsequently they are integrated from the overall system. This level focuses on deciding which modules are needed for system the specifications for those modules and how these modules are that interconnected. Context Flow Diagram (CFD): A Context Flow Diagram is a top level (also known as level 0) data flow diagram. It only contains one process node (process 0) that generalizes the function of the entire system in relationship to external entities. A Context Flow Diagram is a diagram that shows the inputs and output of a system. It shows all the external entities with the system and the data flows between these entities and the system.
Order ,
Bill,reports
Generate bills,
View products,
Provide goods Supplier details
Order details,
Add products, Data base Supplier Admin Customer
Supply products
Sales and inventory management system Gives order to, enquire give order to