Profit Sharing and Other Ways to Reward Operational Excellence.

Keen to get feedback on anyone currently using profit sharing with long term "site based" suppliers (services related) to keep them honest when bidding on jobs. An example may be where you have a schedule of rates in place. Vendor quotes based on hours. They come in cheaper vs the quote and the customer provides a share of the difference back. I see there potentially being a challenge around inflated quoting. Keen to know what other methods may be used to drive additional efficiency on costs.