At the same time, you suspect that people are taking vacations when they are calling in sick. So you worry if people are taking random days off. You did actually post that.
The nice thing about separating the vacation from sick days is that I can schedule my vacation to the limit and not worry about getting sick. I'm betting that you have a lot of people taking time off in December, since they have so much left over- given you are forced to conserve days in case someone gets sick in your family.
I don't have to worry anymore about whether people are actually sick or not. That's one of the reasons we did away with our old system 20 years ago.
Invariably someone would call in sick, use one of their sick days we used to give them, and then two days later another employee would be in squealing, reporting that the "sick" employee was seen at Walmart or the movies or something. Honestly, I got "sick" of dealing with it.
Here's the thing. For those places of employment that still separate sick days and vacation, practically speaking the employees are doing it my way, except they are only doing it halfway, and not to their benefit.
If an employee gets 10 sick days, and uses them all up by August, what are they going to do when they get sick in November? They're going to use one of their vacation days, if they still have any left and if they want to get paid for the day they're gone. Thus, the employee essentially combines that vacation day into their sick days. Fine. Employers don't care.
But employees never got to do it the other way. If they had only used 4 sick days up by December, those six days just sat there. Employees weren't allowed to just combine them with vacation days. They had to use them only when they were sick.
My way is better.
As for our experience with respect to taking time off, most employees will schedule a week or so sometime in the first 7-8 months of the year, I suppose for family vacations. Then, throughout the year, employees will sprinkle in days here and there, frequently to try to give themselves a three day or four day weekend.
The experienced employees usually hang onto a few days for December, in case they get sick. If things are really busy and an employee has a couple of days that I haven't been able to let them have off, I'll let them use them up the next year. It actually has worked really great.
The only argument that I've heard used against it is that it encourages sick employees to come to work. I suppose that could happen, but it could also happen when you give an employee a set number of sick days and a set number of vacation days, and they've used all of their sick days and don't want to use their vacation days. In any event, we haven't had a problem with that.