It all boils down to having financial planning since it is important to track all your expenses and income so you can further assess the performance of your business. Having keeping records is one way to go since it could give you an image of the business' financial flows. I think in the situation of the barber, having personal financial planning is important since it could be a problem of how he personally manage his own money. It is important to any business and individuals to track their expenses and have financial planning so that they can really see what to do and also to view their standing in terms of financial secureness.
In this case, I wanted to say that for this barber, in addition to keeping financial records, he must also separate personal expenses and the budget of his business.
To fix the problem, you need to know its source, what is the reason for the deficit in his budget. But in any case, if he is faced with this problem, it means that he does not have enough income that he receives for a comfortable life, and he will need to think about how to increase income. It is possible to expand his barbershop and hire a few more barbers. From identifying the cause, the problem will not go away by itself, it will be necessary to work on its solution.