Exercise: employee timecards

In many businesses, employees may work on a number of different projects. Each week, they will submit a time card that lists each project on a separate line, along with the number of hours that they have worked that week on that project.

Model the information provided by completing the following steps.

  1. Start by identifying and describing each class in English. Note, this is following a top-down design where you first model all the objects in the enterprise and then you determine how they interact.
  2. Continue by drawing the UML class diagram by drawing the classes, but avoid filling in the attributes for now, just name the classes. Include association classes if required.
  3. Next, determine what relationships exist between the classes you identified. Draw each association in the diagram including the multiplicity constraints and describe in English (both directions) to make sure you've correctly modeled the information given.
  4. Now complete each class by filling in the attributes and their corresponding data type.
  5. Map the UML class diagram to the relational model by drawing the relation scheme diagram. Be sure to model all constraints such as any non-null attributes, primary key, and foreign key.

The solution to this exercise may be discussed in class by your instructor or posted online at a later date.