The Tube Vending Machines

There are likely to be a lot of posts in this category in the fullness of time, I've been saving myself

I'm going to start with something that is going to become a bit of a running topic, with daily status updates. On the Northern Line, Northbound platform at Waterloo, by the entrance closest to Kennington, there is a vending machine which promises all kinds of Cadbury goodness, as well as Trebor Softmints and even cough sweets. Aside from questioning the whole point of this machine in an environment which, during the summer, has an ambient temperature in excess of 30 celsius (umm, sticky chocalate) and yet not providing a dispensing machine for bottled water (instead, you are advised to bring your own - handy when you're overcome by heat halfway through a long journey), I have a big gripe with this machine. As a web developer I often find my work being criticised on grounds of useability - people have high expectations for websites that are easy to use, transparently organised and yet allow the user to complete some complex task. What is clear to me is that no-one thought about useability when designing this vending machine. There are two key flaws:

1. The coin refund is not linked to the coin input, this means it is impossible for the machine to refund the money you have just put into it if it is out of change (and displaying the 'Exact Change Only' message).
2. There is no indication of what is in stock and out of stock, this means the only way to find out if there's anything in the machine is to put money into it and start asking for chocolate.

Now, if this machine was maintained regularly there would be little chance for either of the two situations mentioned above to happen, let alone both happen together. And yet, every day this week on my way home from work I have looked at the machine and it has contained non-refundable credit and not contained any chocolate. So henceforth in my weblog I will record the state of the machine every day that I pass by:

Message on display: Exact Change Only
Credit in machine: £1.40
Chocolate available: None

So it begins...