Create Nested Rule

In this example, we will determine whether a shipping fee should be applied for a product. The decision will be based on the following criteria:

• The product's discount rate (retrieved from the previously defined discount rule)

• The product's category (e.g., fashion )

Kurallar şöyle:

1. For products with a discount rate of 25% or higher → Shipping is charged

2. For all products in the fashion category → Shipping is always charged

3. For products with no discount or a discount rate below 25% → Shipping is free

Product Category	Discount Rate (%)	Shipping Fee
Fashion	Any	Charged
Any	≥ 25	Charged
Any	< 25	Free

Note: The fashion category always has priority. This means that even if a fashion item has only a 10% discount, shipping will still be charged.

Input and Output Definition

• Input:

  • product_type

  • discount_rate (Discount rate, value returned from the discount rule)

• Output:

  • paid (boolean) — Indicates whether the shipping fee will be charged

    • true → Shipping fee will be charged

    • false → Shipping fee will not be charged

• We set the default value of the paid return parameter to false (i.e., shipping is free).

• However, since shipping is always charged for the fashion category,

• we create a separate decision table based on the product_typeparameter.

• In this decision table, when product_type = fashion, the paid value will return true (shipping charged).

• In the decision table, when the product_type value is "Fashion",

• The return parameter paid is set to true (i.e., shipping is charged).

• Since the shipping fee needs to be determined based on the discount rate, we create a new decision table named "Based on Discount Rate".

• In this table, the discount rate parameter will be defined using the Greater Than or Equal To (≥) comparison operator.

• Thus, shipping fees can be applied for cases where the discount rate is equal to or greater than the specified value.

If the discount rate is ≥ 25%, then paid is set to true (shipping fee charged).

Rule definition is complete.

Testing

• Category: Toys

• Amount: 100

Status: In the discount rule, a 30% discount is defined for the Toys category. In the shipping fee rule, it is decided that shipping is charged for discounts of 25% or more.

Result: According to this test, since the discount is 30%, the shipping fee will be charged (PAID = true).

• Category: Fashion

• Amount: 10

Status: In the discount rule, it is defined that a 15% discount applies to amounts between 0 and 500 TL for the Fashion category. In the shipping fee rule, there is a rule stating that shipping is always charged for the Fashion category, and this rule has priority in the order.

Result: Therefore, regardless of the discount rate, the shipping fee will be charged (PAID = true).