MIS602 Data Modelling and Database Design  

Assessment 2 Data Implementation - Case Study  

The following case study models a mobile phone company. The company has a number of phones that are  
sold by staff to various clients. Each phone comes with a plan and each plan has a number of features specific  
to that plan including:  
• a call charge in cents per minute (this does not apply to all plans)  
• a plan duration in months  
• a break fee if the customer leaves the plan before the end of the plan duration  
• a monthly data allowance in gigabytes  

Assumptions that are made for the assignment are:  
• mobile phones are locked to a plan for the length of the plan duration  


Entity-Relationship Diagram  




Relational Model  

CUSTOMER CALLS MOBILE STAFF TOWER CONNECT PLAN  
CustomerID CallsID MobileID StaffID TowerID ConnectID PlanName  
Surname MobileID PhoneNumber Surname Location TowerID BreakFee  
Given CalledNumber BrandName Given Bandwidth CallsID DataAllowance  
DOB CallDate Joined DOB MaxConn MonthlyFee  
Sex CallTime Cancelled Sex SignalType PlanDuration  
PhoneHome CallDuration PlanName Joined CallCharge  
PhoneWork DataUsage PhoneColour Resigned  
PhoneFax CustomerID Address  
Address StaffID Suburb  
Suburb Postcode  
State Phone  
Postcode SupervisorID  
Commission  
RatePerHour