A laboratory has several chemists who works for one or more projects. Chemists also may use certain kinds of equipment on each project. Same equipment may be assigned to one or more chemists. Projects may be assigned to more than one chemists depending upon their size and type. Suppose you are modelling the database solution with following enterprise model:
CHEMIST (chemist_ID, name, address, phone_number)
PROJECT (project_ID, project_name, start_date, end_date)
EQUIPMENT (equipment_ID, equipment_name, qty)
The organization wishes to record Assign Date â€“ that is, the date when a given equipment item is assigned to a particular chemist. A project can be assigned to the chemist at any time after it has been started and organization wishes to record Schedule Date- that is the date when a chemist is assigned to a particular project.
The competition in manufacturing have been intensified and competitors seemed to respond more rapidly than â€œPerfect Value Furniture Company (PVFC)â€. PVFC is manufacturing very high quality furniture and carrying high reputation in the market. However, in recent years the sales has fallen down drastically and there are many complaints reported by customers for errors in invoice, wrong items delivered or product not available in stock etc. A research team at PVFC has identified a root cause of all issues as their data management system. PFVC is maintaining all data about customers, orders, and products in a spread sheet based file. To address the problems and to make their data management system accurate, consistent, integrated and efficiently manageable, PVFC has decided to migrate its file system based database to modern relational database management system.