One of the powerful feature (but look simple) in Salesforce is Sharing. Yes, it just records sharing and many of us as Salesforce admin/consultant not really care about "Sharing Settings". But, you need to configure it correctly to make sure your sales reps are not fighting.
I will share a little on sharing for Contact, Opportunity, and Case, based on my experience.
If you go to Account Sharing Rules, you will find Contact, Opportunity, Case sharing.
Then if you go to Contact, you can find Contact Sharing Rules, the same applies for Opportunity and Case.
So why double? Is it the same thing? Yes and No.
For example Contact:
- Yes, when Contact owner = Account owner, so it will be same.
- No, when Contact owner <> Account owner, why?
In Account sharing rule, if the Account owned by Mike, and contact tagged to that Account is owned by Bruce, the sharing rule in Contact will not effect for Bruce.
But, if the sharing rule is in Contact, no matter who owned the Account, the sharing rule in Contact will ALWAYS effect.
So, which one is the best? No right answer, it will be based on your business requirements.
Hope this makes sense and help.