The price of a ProductOffering or a bundle may be simple or quite complex.  A simple price could be the charge associated with the monthly rental of a cable modem. Or, a price could encompass many different components. A typical introductory wireless offering, for example, will have an activation cost, a monthly cost, a number of free minutes, a cost for extra minutes, and some sort of promotional component. It might also include a corporate discount for business users. Each of these elements must be described in order to paint an accurate picture of the overall price charged for any ProductOffering.  <br/>This part of the SID model presents a set of components that can be combined to offer a complete and accurate description of the price charged for an offering. A secondary consideration is to define those components in such a way that they can be readily implemented in a typical billing system.<br/>A ProductOffering may have any number of prices, each of which is made up of a single component or a composite of a number of components.  The Product Offering Price model employs the composite/component modeling pattern used throughout the SID to represent simple and complex prices, as illustrated in the figure below.<br/>ProductOfferingPrices can be dependent upon a ProductSpecCharValueUse as shown in the figure above.  For example, a provider may offer a photo printing service for mobile phone pictures.  The price may depend on the size of the photo or the type of finish of the photo; $.20 for a 3 by 5, plain finish, $.25 for a 5 by 7, plain finish, and so forth.  The values associated with the size (3 by 5, 5 by 7, and so forth) and finish (plain, glossy, matte, and so forth) can be stored as ProductSpecCharacteristicValues.<br/>ProductOfferingPrice, which may have a complex structure (composition) and involve complex billing / rating capabilities, could be defined in a ”pricing catalog” as a reusable component pre-defined for given ProductSpecs and then selected for use by the ProductOffering to be published in the ProductCatalog.<br/>The ProductSpecification to ProductOfferingPrice association allows the use of the ProductOfferingPrice entity as a “pricing specification component” defined for ProductSpecifications.  For a given ProductSpecification, the “pricing catalog” may contain several pricing component candidates for use. When defining the ProductOffering, pre-defined pricing components (ProductOfferingPrices) for ProductSpecs, can be selected to value the ProductOffering.  Existing pricing components may also be individually altered or new ones defined for a given ProductOffering.<br/>Figure Pr.8 also shows an association between ProductOfferingPrice and PriceEvent.  The PriceEvent business entity represents an occurrence (happening) or schedule that triggers the creation of a billing charge for a ProductOffering.  For example, a PriceEvent instance may represent the end of a month when monthly recurring billing charges are created.   In some cases, the creation of a charge associated with a ProductOfferingPrice may be triggered by multiple events.  For example, a penalty (ProductOfferingPrice) may be triggered by over- or under-usage of a service.  Under- and over-usage are represented as two separate PriceEvent entity instances.<br/>