In a perfect world, every carrier would be able to deliver precisely against ALL contractual commitments.
In reality, there are so many potential points of failure that it’s impossible to meet 100% of those obligations. In fact, studies have shown that up to 5% of shipping expenses are eligible for a refund due to carriers’ failure to meet these obligations.
What that means is that you should be seeing substantial monthly refunds from your carriers.
Are you seeing refunds? Do you have a parcel audit software system in place that monitors individual shipments?