Product Specification Field Decomposition
Each product has a modeled set of characteristics within a product catalogue. When a product is decomposed to a plan item, the default and the instance characteristics are copied over into the User Defined Fields (UDFs) of every plan item. This allows the information to be reused later when the plan item is executed.
For example, consider a product "Line Access 5MB" has characteristics modeled such as Speed=5, QOS=4, IPAccess=false. These are all modeled as instance variables. When an order is submitted for Line Access or is part of a bundle, the plan item uses the same instance characteristics copied as UDFs into the plan item. When the plan item is executed, the UDFs can be passed to the service call.
When an order is made the characteristics are visible as UDFs for each order line. When you submit the order, the UDFs are converted into UDFs for the new plan items and if the order line is a bundle then those items can have UDFs as well which are copied to the execution plan. All theses UDFs can be used later through the service call.