Computer Repair ERD Case

ABC Computers has been serving all of Acadiana's Computer Repair, Service and Sales needs since 2001! Their Services include: Computer Repair, Laptop Screen Repair, Virus Removal, On Site Compute Services, and iPhone Repair & iPad Repair.

The owners of ABC Computers would like to keep track of the repair jobs for all the equipment they repair, the parts used for each repair job, and the customer’s information. Each repair job refers to only one equipment, but the customer could bring in more than one equipment. Each repair job could entail the use of many parts but doesn’t necessarily use one every time. A part could be used in many different equipment.

You have identified the following Business Rules so far:

1. A customer can have one or many equipment.

2. An equipment is owned by one or and only one customer.

3. An equipment is brought in for one or many repair jobs.

4. A repair job entails one and only one equipment.

5. A repair job uses zero or many parts

6. Each part is used in zero or many repair jobs

Phase 1: Define Entity Classes and Primary Keys

Phase 2: Define Relationships among entity classes

Phase 3: Define the cardinality among entity classes

Phase 4: Create an Intersection Relation

Phase 5: Create the final structure