Diagramming is a "top down" user process.  Take the following user provided information and draw the appropriate ERD.  Follow the Simple Procedure for ERD diagramming to design an ERD using the following user provided information.    Remember the ERD will eventually turn into the design for a database from a top down view.   Make sure you resolve any many to many conflicts.   Label an identifier or primary key and all pertinent attributes given.    If an attribute is not readily apparent from the user information, then make one up that makes sense for the particular entity.   Therefore, all entities should end up with at least an identifier and another attribute that makes sense.

Big Builders Company Example ERD Problem

Entity Relationship Diagramming is a "top down" user process.  Take the following user provided information and draw the appropriate ERD. 

Follow the Simple Procedure for ERD diagramming to design an ERD using the following user provided information.    Remember the ERD will eventually turn into the design for a database from a top down view.   Make sure you resolve any many to many conflicts.   Label an identifier or primary key and all pertinent attributes given.    If an attribute is not readily apparent from the user information, then make one up that makes sense for the particular entity.   Therefore, all entities should end up with at least an identifier and another attribute that makes sense.

Please use a drawing tool of some type to show the ERD diagram (Word, PowerPoint, and Visio all work well).   I want you to get in the habit of drawing these with a computer instead of by hand, as this will be important as we get to more difficult examples.   You may use either the ER-Model or Crow's foot model, though answers will be provided in the Crow's foot by the instructor.   Make sure you show entities, relationships, cardinality, and optionality.

Big Builders Company Example

Big Builders Company is a builder/developer of residential buildings on which they need to keep information.  In addition to other information, they assign unique project numbers to each of the projects they have.  Each project is assigned to only one project manager (identified by a unique employee number with other information, such as name).  Project managers usually have several projects under their direction at one time.  Each project is usually associated with several subcontractors.  These subcontractors (identified by a unique identifier with other information) specialize in only one line of work (example - electricity, flooring, etc.).  Specializations are identified by a unique code and include other information.  Big Builders likes to use subcontractors with whom they are familiar, so a given subcontractor will often be hired to work on several projects during the year.  However, they have too many projects to permit one subcontractor to supply all of a particular specialty (for example, they need more than one electricity subcontractor).  Projects are usually financed by banking loans.  Each project may be financed by several banking loans, although a specific banking loan is restricted to a single project.  Banking loans are identified by a unique loan identification number and also include other information such as amount, payment amount, etc.