I am re-making my accounting software (the idea is to support windows/web and mobile platforms) and I need to clarify something regarding the business model. Up to now my software was nott "properly designed", so I need to redesign it in order to make it scalable and multi platform. Currently I am creating a business model, and I am not sure where to put what.
I think I am ok with main entities so far, but, as with most of the software, there are usually some statistical information which is presented to client. Example, show all invoices for which payment day is overdue. Or, show me the sales amount per day/month/client, show me stack movement per month/year, etc. Many examples like this. In the past I have done this by executing stored procedure and populating some collection with returned data.
How will this fit into the model? What is the right approach? Should I have a class for each of the different data needed?