I have an external web service (owned by the company) which my SuD integrates with. I also have relational database:
Client tier --> Web / Business logic tier (middle tier) ----> Data tier
The database sits on the Data tier.. But where would the web service sit in this scenario? Should the data tier actually be an EIS which includes database and web service?? Or is it simply seen as an external system, not part of the main tiers?