I have always maintained that exceptions are a myth, much like scrap inventory. We all have policies regarding how we deal with things like customers wanting changes made or employees wanting some form of special consideration.
We are often asked to make an exception to these policies. An employee may want to come in late or leave early. Or a client may ask to change the door style halfway through the job. Whatever is being asked, be careful about how willing you are to accommodate the request. Because the easiest way to create an expectation is to make an exception.
Once you have allowed the variance, everyone is going to figure that they too are entitled to the same consideration. “You let Bob come in late last week, how come I can’t come in late tomorrow?”
So, before you make an exception, think about whether or not you are willing to establish a new policy. The exception will become the new paradigm.