I use an "Error" schema in my data mart. I re-direct error rows from the SSIS data flow to an identical table in the error schema. This makes sense to me because the domain of the data is the same and is used for the same application. However, I'm not a fan of mixing different data domains or different application data in the same database using different schemas. For example, I have seen "staging" and "prod" schemas live in the same DB. I typically wouldn't do this because the two serve different purposes with different recovery & support models. Of course, when you are being gouged and screwed for third-party, per-database support I can understand the desire to stuff everything into one database using different schemas.