Possibly something else to bear in mind. The company I used to work for delivered their own products (own account) and had a fairly relaxed attitude to delivery schedules, customers were given a 3 day delivery window which worked OK as our customers probably needed us as much as we needed them. Then we outsourced our transport and suddenly we were telling customers they could pick their own delivery time and date, and the haulier who took it over had to fit in with this, or be “fined” for late, or even early deliveries. It’s a lot easier for the manufacturer or whatever to dictate terms like this when the cost of doing so isn’t their problem!