An insurance company writes term life insurance policies for its customers. It uses a computer system to maintain the policies and bill customers. Figure 1 below shows the context data flow diagram for the system.

Figure 1


FILES

CUSTOMER FILE. A direct access file consisting of one entry for each customer:

• customer number, 8 digits
• customer name
  • first name, 10 characters
  • last name, 15 characters
• customer address
  • street address, 30 characters
  • city, 15 characters
  • state, 2 characters
  • zip, 9 digits
• customer birthdate, MMDDYYYY
  

POLICY FILE. The direct access policy file consists of one entry for each policy:

• policy number, 10 digits
• customer number
• effective date (when policy took effect for the first time), MMDDYYYY
• expiration date (when policy expires), MMDDYYYY. One year is added to this date whenever a check is received to pay for renewing the policy.
• rate per year (how much this policy costs per year), up to $9999.99
• policy value (how much the policy will pay out when the customer dies), up to $999,000.00, always in amounts evenly divisible by $1000.
• beneficiary details, up to ten for each policy, with each beneficiary detail consisting of
  • beneficiary name (same format as customer name above)
  • beneficiary address (same format as customer address above)
    

RATES FILE. A table of ages and associated rates per year per $1000 of insurance. Each rate entry consists of:

• age, up to 120 years
• rate per $1000 of insurance, up to $500

FUNCTIONS

ADD NEW CUSTOMER. When a new customer applies for coverage, the next available customer number is obtained from the customer file. The transaction is edited to make sure a name and an address are present and the birthdate is a valid date. This information is then stored in the customer file.

ADD NEW POLICY. Before a policy can be written, the customer must have been added to the customer file first. A new policy transaction consists of the customer number, the date the policy is to take effect, the face value of the policy (always a multiple of $1000), and one or more beneficiaries who will receive the face value amount when the policy holder dies.

The next available policy number is obtained from the policy file. The new policy data is edited as much as possible, including checking for a valid customer number, editing the start date, editing the policy value, and checking for the presence of at least one beneficiary and address. The birthdate is subtracted from the policy start date in order to calculate the customer's age. The age is then checked against the rate file in order to obtain the rate per $1000 of insurance. This is then used to calculate the rate for a policy is as follows:

The age is always calculated based upon the customer's age on the date the policy takes effect. The expiration date of the policy is initially set to the start date, but it will be updated to one year later as soon as the customer pays for the policy.

Additionally, the information above is used to immediately produce a bill for the new policy. The bill is mailed to the customer.

APPLY CUSTOMER PAYMENT. A customer payment consists of the policy number and the amount of the payment. When a customer payment is received, the policy number is verified against the policy file. The yearly rate is calculated, again using the procedure detailed above, but this time using the expiration date instead of the start date (in this way, the payment can be applied accurately regardless of whether it is for a new policy or a renewal). The payment amount must exactly match the yearly rate or it is rejected. The policy record in the file is updated with the new expiration date (one year later than the old one) and the new yearly rate.

PRODUCE RENEWAL NOTICE. Once each month, renewal notices are mailed to all customers whose policies will expire within the next three months. The renewal notice contains all relevant information about the policy, including the new yearly rate.

ADDITIONAL FUNCTIONS

PRODUCE CANCELLATION NOTICE. Once each month, cancellation notices are mailed to all customers whose policies are one month overdue; that is, the current date is 30 or more days past the expiration date.

UPDATE CUSTOMER RECORD. Customers occasionally change their names or addresses. When such information comes from the customer, it is edited as much as possible, then used to update the customer record.