It sounds like the Becky Moran points system from London. That is too 'one size fits all' for my taste and many others. Learning to recognize the early signs of nearing your limits so you can switch tasks is another system. The point system does not have adjustments for individual issues. Your bad sleep vs good sleep days will have different applications of points. Learning to recognize the early signs works whether you have had good sleep or not. It also works with those tasks and activities that do not fit the points system.