Question

Develop an EER (ER) model for the following situation using traditional EER notation.  You have been hired by a new start-up company, IT Consulting – a company that consults with corporations to determine their security needs. You came up with the following set of entities, attributes and business rules:

CONSULTANT

2 types of consultants – business consultants and technical consultants.  Business consultants first work with a company for security needs, technical consultants perform services according to specs developed by business consultants.

Attributes of Business consultants:  Employee_ID (primary key), Lastname, Firstname, Street City, State, Zip, home phone, date of birth, age, years in business, type of business, degrees received

Attributes of Technical Consultant:  Employee_ID (primary key), Lastname, Firstname, Street City, State, Zip, home phone, date of birth, age, technical skills,

degrees received

CUSTOMER

Customers are businesses that have asked for consulting services.

Attributes:  Customer ID (primary key), Company Name, Company Street, Company City, Company State, Company Zip, Contact Name, Contact Title, Contact Telephone, Business type, number of employees

LOCATION

Customers can have multiple locations.

Attributes:  Customer ID (primary key), Location ID (part of primary key), Location Street, Location City, Location State, Location zip, location telephone, building size (square feet)

SERVICE

Service is performed for a customer at one or more locations.  Before services are performed as estimate (cost) is prepared.

Attributes:  Service ID (primary key), description, cost, coverage, clearance required

Additional Business Rules (these can become entities in your tables if needed-probably will!!)

Estimates – attributes of Date, Amount, Business Consultant, services and customer

Services performed – attributes of date, amount, technical consultant, services, customer

Assume the following:

A customer can have many consultants providing many services.  You want to track actual services performed and services offered – therefore, two relationships between customer, service and consultant.

Answer 1

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