Plan the round, not the day. Three deliveries at opposite ends of town consume everything, while three in the same street are an hour — and the difference between those two versions of a Tuesday is entirely in the sequencing.
Keep the showroom and the warehouse in one system. Selling a model that exists only as a display unit costs a phone call, a refund and a household that tells everyone, and it happens whenever two lists are kept apart.
Record the serial number and the installation at the point of sale. Two years later, a warranty claim is decided by whether that information exists, and reconstructing it from a paper file is how shops end up paying for repairs the manufacturer should have covered.