I am familiar with Dimensional Modelling but here is a type of question I have not had to address before and I don't quite know how to model/handle this.
We supply financial products to customers. A customer applies through an "Application".
Depending on various factors, an Application may require an action from an Operator in order to progress. We call this a "Task".
Once a "Task" is fullfilled, another "Task" maybe necessary and there may be a delay before that next task starts (the end of one task is not necessarily the beginning of the next).
Tasks are grouped in Categories.
We would like to be able to answer questions like: "What were the Applications that moved from a Task of category X to a Task of category Y within a particular period?"
My guess would be that I will have a Fact table of Tasks with the following columns (foreign key to dimension tables)
- TaskApplication -> DimApplication (which application does this task applies to)
- Task_StartDateTime -> DimDate
- Task_EndDateTime -> DimDate
- TaskType -> DimTask (Type and Category)
My difficulty is then: how do I (quickly) identify all applications that moved from one task of type X to another of type Y.
Am I right in thinking that I should have a column in my fact table indicating the Task Rank for each Application (first task for that application is 1, second 2, etc)?