What are you going to have this year "A Point of sale system" or a "Point of Failure system".
Remember something like this.
It would have cost a lot in goodwill as well as money.
Now, it is essential to check that all the equipment you propose to use over the Christmas period is working? This is particularly true of some of the old POS machines that people bring out of the cupboard at present. Please check them to make sure it all works? Furthermore, check the cables. Equally important that your Internet connections are where you need it? I suggest you try it all out now.
Have you tested all your system, now before Christmas day hits?
How much does someone want to bet with me that several of our clients, on the busiest days of the years, when computer engineers, if you can get them even on double and triple time, will be called out to fix problems that should have been checked and fixed now!
You want anything working over the coming season.