1. Draw an E-R diagram for the following situations.
From discussions with hospital staff, reviewing hospital documents and studying existing information systems, the study team developed a list of business rules describing the policies of the hospital and nature of the hospital's operation that govern the relationships between entities. Some of the rules are:-
• A facility maintains a number of laboratory(ies) : radiology, electrodiagnosis, hematology and so on.
• A facility contains a number of wards (obstetrics, emergency, rehabilitation, geriatrics, etc).
• Each ward is assigned a certain number of staff members (nurses, secretaries, etc); a staff member may be assigned to multiple wards.
• A facility staffs its medical team with a number of physicians. A physician may be on the staff of more than one facility.
• A physician treats patients and a patient is treated by any number of physicians.
• A physician diagnoses patients and a patient is diagnosed by any number of physicians.
• A patient may be assigned to a ward (outpatients are not assigned to a ward). The hospital cares only about the current ward a patient is assigned to (if assigned at all).
• A patient uses medical/surgical items, which are supplied by vendors. A vendor also provides supply items that are used for housekeeping and maintenance purposes.
• A laboratory performs tests about patients.