Smooth Telco normally markets a range of mobile phones as individual items. For a limited period around February 14th, it decides to market, a BundledProductOffering called the Valentine Special, one model with a special red cover, boxed in pairs and accompanied by two champagne glasses. As an added attraction, the deal includes a discount for calls made between the telephone numbers allocated to each pair for a set period. It is a huge success and likely to be repeated the following year when a new ProductOffering with the new valid time period will be created. These ProductOfferings exist side by side with the standard ProductOffering for the mobile phone model when the phones are sold individually. <br/><br/>A question arises with this example.  Should the Valentine Special or any BundledProductOffering have an associated ProductSpecification? <br/>One alternative could allow for this by representing the association between ProductOffering and ProductSpecification as 0, 1.  But this association could lead to a SimpleProductOffering not having a related ProductSpecification.<br/><i>Note: This way of doing isn’t the one recommended by SID, so this relationship isn’t in the RSA model as only one solution can be in the model.</i><br/><br/>A better representation of this association would be to only relate a SimpleProductOffering to a ProductSpecification as shown in the following Figure. This association allows a BundledProductOffering to not have a related ProductSpecification while requiring that a SimpleProductOffering has one.<br/>