Does anybody face the issue with Design Validation and related overheads?
When we deliver a Solution we have a lot of so-called Streams (usually 3-8, average 5). Each Stream is responsible for its functional Module (e.g. Asset Management, CRM, Billing etc.) and prepares Technical Design for it.
The issue is that the functionality across the Streams is very interconnected and there are a lot of End-to-End Scenarios, which are not explicitly documented.
The approach we use to validate all this stuff is a manual cross-stream review, which is really very time consuming and error prone. Furthermore, as up to a human factor, it is physically impossible to do such validation, and we find out about gaps only during the last testing Phase (End-to-End one) when everything is already implemented (yes, we are waterfall). And you know what the cost of such gaps is...
How do you solve this issue? Special tools, techniques, methodologies etc.?