Case Study in Variation: An International E-Tail System

Suppose an e-tail system must process sales orders in several different nations. Initially I have to handle just the United States and Canada. I look at my requirements and see several things that vary. I note these in Table 20-1.

Table 20-1. Different Cases Depending Upon Residence of Customer
Case Procedure
U.S.A
  • Calculate freight based on UPS charges.

  • Use U.S. postal rules for verifying addresses.

  • Calculate tax based on sales and/or services depending upon locale.

  • Handle money in U.S. $.

Canada
  • Calculate freight based on main Canadian shipper.

  • Use Canadian postal rules for verifying addresses.

  • Calculate tax based on sales and/or services depending upon Canadian province taxing rules (using ...

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