Conceptual Data Model Assignment
Metropolitan Housing
1. The Metropolitan Housing Agency (MHA) is a nonprofit organization that advocates the development and improvement of low-income housing. MHA operates in a metropolitan area of approximately 2.2 million people in a mid-western city.
2. MHA maintains data about the location, availability, and condition of low-income housing in eleven different census tracts in the metropolitan area. Within the boundaries of these tracts are approximately 250 different buildings that provide low-income housing. On average, each building contains twenty-five apartments or other units.
3. MHA keeps data about each census tract including geographic boundaries, median income of the population, elected officials, principal businesses, principal investors involved in properties in that tract, and other demographic and economic data. It also maintains a limited amount of data about crime. For each building, MHA stores the name, address, size, owner(s)s name and address, mortgager(s)'s name and address, renovations and repairs, and availability of facilities for handicapped people. In addition, MHA keeps a list of each of the units within each building. This list includes the type of unit, size, number of bedrooms, number of baths, kitchen and dining facilities, location in the building, and any special remarks. MHA would like to maintain typical information on the occupants to help with statistical and demographic reporting and average occupancy rates for each unit, but it has been unable to collect or store such data to date. MHA does, however, keep data about whether a given unit is occupied.
4. MHA serves an information clearinghouse and provides three basic services. First, it works with politicians, lobbyists, and advocacy groups to foster the development of legislation that encourages the development of low-income housing through tax incentives, developmental zoning preferences, and other legislative inducements. To accomplish this, MHA provides information about low-income housing to state, county, and city governments. Second, MHA strives to raise community consciousness about the need for low-income housing through electronic networks, advocacy speeches, seminars, displays at conventions, and other public relations activities. Finally, MHA provides information about the availability of low-income housing to other agencies that work with the low-income and homeless populations.
5. MHA wishes to consolidate this information into an agency database application. You are to do the design work. Develop a conceptual data model for this case using the entity-relationship methodology. Consider the mission of the agency and what they are trying to accomplish. Make sure you label your entities, include or list all attributes and note any assumptions you have made. Submit a graphic representation of the data model. You may use a tool like visio or you may hand draw the diagram. Make sure it is neat and readable.