The idea of calculation framework starts off with understanding of two main concepts: Calusage and Calmethod. CALUSAGE_ID DESCRIPTION -1 Discount -2 Shipping -3 Sales Tax -4 Shipping Tax -5 Coupon -6 Surcharge -7 Shipping Adjustment -8 Installment Adjustment List of Task Application Initialization Combination Qualification Calculation Summation Finalization General flow of calculation methods The general flow of calculation methods, when they are used as part of the order process, is as follows: 1. InitializeCalculationUsage 2. ApplyCalculationUsage calls: a. CalculationCodeCombine calls: i. CalculationCodeQualify b. CalculationCodeCalculate calls: i. CalculationRuleCombine calls: