A Project ID identifies each project. Each project is also given a short title that may or may not be unique and may be given a longer description.

Case: A Project ID identifies each project. Each project is also given a short title that may or may not be unique and may be given a longer description. A project manager must manage each project and may have many team members assigned to work on it. Some of the team members may work on more than one project. The project has a start date and scheduled completion date. The project also has a total estimated cost. Employee ID identifies people in the company, although the project manager needs to know the name, phone number and e-mail address assigned to each member of his/her team. The project manager also needs to know when an employee is officially assigned to a project and when is relieved from a project. An employee can be a full-time employee or a part-time employee. For a full-time employee, information on the medical benefit provided by the company to the employee is kept. For a part-time employee, information on the contact term and duration is kept. Each project consists of several tasks, identified by a Task ID. Each task has a scheduled start date and a scheduled completion date. As the tasks are performed the actual start and end dates are also recorded. Each task has a planned duration. A task may also have one or more tasks that must precede it.

Portfolio Question

Based on the case above, produce an Entity Relationship diagram (ERD) that models the problem which includes: 

1. all entities, relationships (including relationship names) and attributes;
2. primary (underlined) and foreign (italic) keys identified; 
3. cardinality and participation (optional / mandatory) symbols; and 
4. assumptions you have made, e.g. how you arrived at the cardinality/participation for those not mentioned or clear in the business description, etc. 

The E-R should be completed using the standards/conventions of this course (crow's feet)