If you would like to see your on-time performance that is shared with your customers, click on the Dashboard tab.
Scroll down to the bottom left to view the supplier on-time performance widget. It should look something like the below image.
On-time performance is calculated by comparing an order's estimated ship date and the order's actual ship date. Both of these inputs are provided by the supplier in the Ship Date milestone. To learn more about the Ship Date milestone of an order, read the full article here.