Ask HN: Are there any sites where businesses can collaborate with suppliers?

I have been tossing a few business ideas around in my head for the past few days, and one that I am thinking about is a kind of social network for businesses and suppliers.

Without going into too much detail, the site would let businesses create a profile and then connect with other businesses on the site. It could be used to find suppliers and maybe incorporate a rating system so that businesses know which suppliers are good and which ones aren't.

The site could be used to manage the supply-chain as well. Say a company has 4 suppliers. Instead of contacting each one through email and working in a disorganized manner, the suppliers would communicate directly with the company through this website. If there is an issue with a shipment, the suppliers can let the company know promptly and the website would help them find alternative suppliers.

I don't really know the first thing about business to be honest. Does anyone know of a site like this that already exists, or any reasons as to why this would not be a good idea?

Thanks.