What Bottle does

Stock and cylinders

A cylinder is not sold, it is rotated. So stock is always two numbers: how many full, how many empty, and a yard that knows its total but not its fulls knows nothing it can send a van out with.

Where everything is

One table: a row per product, a column per place, sizes grouped under their gas type. Every figure is full and empty, side by side.

Click a product to see the movements behind it: delivered, collected, loaded, coloured by kind, so a figure you do not believe can be traced rather than argued with.

Nobody types the day's movements in

The round already knows what it carried, what went through each door and what came home, so the ledger follows it. Loading a van moves stock from the yard to the vehicle. A delivery moves it from the vehicle to the customer. Empties handed back move the other way. A collection from the yard comes off the yard. The ledger is a record of what happened rather than something somebody keys in afterwards.

Being told before you run out

Set the figure you want warning at against a product, and owners and admins get an email the morning it reaches it, listing everything that is low. It is judged on what is free to sell rather than what is in the rack: forty cylinders with thirty-eight promised to tomorrow's orders is two, and the warning says so. The email is not repeated for a week while stock stays low, so it stays worth reading.

Deposits and rent, which are different things

The trade charges for the cylinder as well as the gas, and does it two ways.

Rent worked out from what was actually held

Rent is for the days a cylinder was held, not for the period. Bottle walks the movements on that customer's account, what went out and when and what came back and when, and adds up cylinder-days. Three cylinders all week is twenty-one. One handed back on Wednesday stops costing on Wednesday. Sizes of one gas type are added together, so two 19kg and a 47kg are three cylinders of rent, at the rent for that gas type.

A customer holding rented cylinders who is not on a cycle that can carry rent is flagged on their record, rather than quietly never being charged.

Who is holding what

Every customer's record says what of yours they have, by gas type, and what that is costing them in rent or holding in deposits. It is the answer to the call that starts "how many of ours has the Crown got?".

What happens next

Rent and deposit credits appear on the period invoice. What is free to sell is what taking an order is checked against.