A company has several departments. Each department has a supervisor and at least one

employee. Employees must be assigned to at least one, but possibly more departments. At

least one employee is assigned to a project, but an employee may be on vacation and not

assigned to any projects. Employee may be assigned to several projects. The supervisors

are not employees, and separate entities should be created for them. The data fields

$($attributes$)$ are the unique IDs and the names of the departments, projects, supervisors and

employees.