TEC has a file of candidates who are willing to work and a list of companies that request temporaries.

If the candidate has worked before, that candidate has a specific job history. Each time the candidate worked, one additional job history record was created.

Each candidate has earned several qualifications. Each qualification may be earned by more than one candidate.

Each time a company requests a temporary employee, TEC makes an entry in the Openings folder. That folder contains an opening number, a company name, required qualification, a starting date, an anticipated ending date, and hourly pay.

Each opening requires only one specific or main qualification.

When a candidate matches the qualification, $($s$)$he is given the job and an entry is made in the Placement Record folder. That folder contains an opening number, a candidate number, the total hours worked, etc. In addition, an entry is made in the job history for the candidate.

An opening can be filled by many candidates, and a candidate can fill many openings