La Jolla Management Company (LJMC) manages several apartment complexes and earns revenues by renting out the apartments in those complexes. LJMC assigns an agent/manager (employee) to each complex (one manager can manage several complexes) to handle day-to-day operations, such as maintaining the property, advertising, and signing rental contracts. This case describes the purchase of the maintenance service process.

Complexes and apartments. LJMC has acquired fifteen and built several more new apartment complexes over the last two years. It identifies complexes by unique names and apartments by the combination of the complex name and apartment#. LJMC categorizes each apartment according to the number of bedrooms and bathrooms, as well as other factors. There are more than 20 apartment categories at present, each identified by a unique category #. Since each complex presents a unique set of luxury appointments and amenities, LJMC determines the standard monthly rental fee by considering both the apartment category and complex, for example, 2 bedroom 1 bath apartments (category 21) rent for $1850 per month in the El Dorado Arms complex (where there is no view and the complex is close to a freeway) but the same category apartments rent for $2850 per month in the La Jolla Cove complex (where there is a view of the ocean from most apartments in the complex).

Maintenance Jobs. LJMC keeps its apartments and complexes in top condition. The LJMC complex managers monitor the condition of the facilities. Whenever the condition falls below LJMC standards, the managers hire contractors to bring the apartment back up to specification. LJMC classifies each maintenance job by job type, and the managers match the job type to the contractor type that can best perform the job. The LJMC manager then selects one specific contractor for the job from that contractor type. Each contractor may belong to several contractor types. Each maintenance job involves either one apartment or the common areas of the complex. LJMC tracks the maintenance performed on apartments and complex common areas. LJMC pays its contractors in full at the end of the month for all jobs that the contractor performed during the month.

Required:

Use the information above to draw a UML class diagram showing the classes, associations, and multiplicities for the maintenance purchase and payments process.