Greenfield data modeling

How data model design is approached depends on whether a pre-existing Foundation application data model exists or whether the application being developed has no prior work, hence no constraints. A name for the latter situation is “greenfield development”. How to work with a Foundation application data model is discussed in the module that follows. The discussion of proactive greenfield data model development begins in this module with some fundamentals.

An often-used technique for developing an object model is to parse a document while extracting nouns and verbs. The nouns would be analyzed to determine suitability as an object and, if so, is that object a specialization of a more generic object. For example, a document might mention a Car which is a type of Automobile or Vehicle. The verbs found in the document could be used for various purposes such as identifying possible cases, processes or steps within a case depending on the granularity of the document.

Avoid developing a data model in isolation. Perhaps a solution already exists. An example is when the price for a certain quantity of items purchased or consumed must be determined. The price per item can remain constant, i.e., unit pricing; or the price per item decrease as quantity increases, i.e., volume pricing; or the price can vary from range-to-range until the quantity is consumed, i.e., tiered pricing. In this example, a data Model that supports multiple pricing strategies would be, in the long run, the most beneficial.

The sample FSG Event Booking application contains an FSG-Data-Pricing class. Instead of maintaining prices per item within the database, preferable for a large number of items, this example maintains item prices within Decision Tables since the number of items is small. If prices were to change over time, the Decision Tables could be circumstanced using an “As-of-date” DateTime property. If prices were kept in the database, an AsOfDate property would need to be added as well as a QtyTo property to support the definition of a quantity range.