Microsoft Business Solutions Great Plains is written in Great Plains Software programming tool: Great Plains Dexterity. Dexterity in turn was built with conception of graphical cross-platform transferability (in time 1992 mostly Mac and MS Windows). Plus Dexterity had database abstraction level (through C programming language). The result of such a shrewd future-looking architecture Great Plains ReportWriter has multiple restrictions and drawbacks. Lets first look at advantages of using ReportWriter:
Seamless integration with Great Plains forms most typical scenario you modify SOP_Long_Invoice_Form or SOP_Blank_Invoice_From and then print your invoices with modified form usually with your logo and changed formats and positions of fields
Parameters Entry Forms. Each existing report (Reports section) has associated parameters entry form.
No Cross-Modules links. You can not associate report with tables from non-related modules. For example you can not have Sales Order Processing (SOP) and Purchase Order Processing data on same report (you actually can but you need Dexterity programmer help)
Custom Reports. You do not have parameters entry interface for your custom reports, but you could use restrictions to restrict selection. Custom reports could be used to export data from Great Plains in text (and then Excel format)