Case Study
National Strata provides strata management service for properties in Sydney.It provides cleaning, plumbing, electrical,gardening,other general repair and maintenance services for many properties. Depending on the contract, one or more services are provided at every property. In case property comprises of townhouses and units, each owner is a client. However, every client within a property is provided same services as per the contract.Contract must be renewed every year for every client.
To manage all these properties, national strata uses many rented office spaces in the proximity of properties they serve across Sydney where staff members work from. For each property, a strata manager is designated. One strata manager can work on many properties, but each property can have only one manager. Apart from strata manager, they have other admin, accounting, cleaning, electrical, plumbing,handy men inrepairand maintenance team.
National strata has a fleet of rental vehicles which staff members can use to attend to service calls. However, some staff members prefer to use their own vehicles. Staff members using company vehicle is assigned the vehicle. Staff members usually get a list of calls they must attend to every day. One or more staff members may attend to one or more service calls.
National strata maintain a shift roster and strata manager consults roster to assign staff members to attend calls. A staff member can be assigned to work on only one shift per day but each shift will have multiple staff members.
The company needs to organize meetings for its clients, for this they must maintain a list of clients along with their names, property details, contact details. They must also collect payments from clients for services provided on a quarterly basis. A list of defaulters is maintained so penalties may be applied as per the by-laws.Company also needs to maintain a list of expenses they incur for each property so accounts can be audited quarterly.
Task 1ER Diagram(10 marks)
•Identify the entities, relationships, participation and cardinality from the above case study.Use UPPERCASE to name your entities and use Capitalisation (of first letter) to name attributes of entities.Underline all primary key attributes and mention all the foreign key attributes.Specify relationship verb.•Resolve many to many relationships.•State your assumptions clearly.•Create an ER diagram using crow’s foot notation in any tool of your choice. Hand drawn diagrams will not be accepted.
Task 2 Normalization(10 marks)
•List all the dependenciesin a dependency diagram including partial and transitive.•Show the determinants and select primary key, foreign key.•Starting with unnormalized data, convert all the tables to 1 NF.Clearly outline the rules for a table to be in 1 NF and provide justification.•Identify partial dependency if any and resolve it.•Identifytransitivedependency if any and resolve it.•Make sure the tables are in BCNF. Explain the rule with tables as example.•Identifymultivalueddependency if any and resolve it.•At each stage list the rules and provide explanation of why the tables are in 2, 3 or 4 NF.