OSS Note impact analysis

Hi Technical Experts,

I would like to knnow how is impact analysis carried our for OSS note implementation.

Example SAP suggest to implement code correction through oss note how does one do impact analsysis of that note?

Another question is once I have implemented oss note and transfer to quality system wherein while testing I find that this code correction does not help.What normally is done for those transport request in Quality server? Is it de-implemented or deleted from there without relesing further to productive system?

Please share your experience and forward releants link if any