There are many reasons for failure. Personally, the one I like best is that someone else is at fault. I’m comfortable with blaming others. Let’s go with that for now.

Every management book I’ve read emphasizes the importance of hiring the right people. Some experts are fond of saying “get the right people on the bus.” I agree. Unfortunately, I’ve got a tendency, once I’ve got the wrong person on the bus, to keep them on the bus.

I’m a big fan of Ram Charan. He’s written extensively on management topics and had a great article in Fortune back in 1999 citing some academic research (I’m catching up on my reading). He reports on the reasons we leave incompetent people in their roles even when we know they aren’t doing the job. This failure to make a change leads to our downfall over and over again.

There are several reasons we leave these people in their jobs despite knowing we should let them go, and I can totally relate to all of them.

Here they are:

1. “This person has to succeed.” The person is so talented, educated, and smart that he or she can’t possibly fail. It’s illogical to think this person can’t do the job. It can’t be his or her fault. It must be something else.

2. “This person’s my guy/gal.” This person has been with you for some time. Maybe the person followed you from your old firm. Maybe he or she has a relationship with you or your family outside of the office. You’re loyal, and you just can’t bring yourself to cut the cord.

3. “I can coach this person.” I can fix this. He or she just needs more time from me and we can bring the performance up to acceptable standards.

4. “I’ve fired a lot of people lately.” Turnover is bad, and you don’t want more of it. You hang on to this poor performer so that you won’t demoralize the rest of the staff and have everyone worrying about the safety of his or her job.

5. “Everyone likes this person.” I don’t want to cut someone out when the local bar, the staff, the clients, and everyone else like the person. Of course, they don’t know he or she isn’t cutting the mustard.

6. “This person’s in the job, and I’ll take the devil I know over the one I don’t.” You’ve made hiring mistakes before, and there’s no reason to think the next person will be any better. It’s easy to get stuck where you are and avoid the risk that comes with making a change.

These are not good reasons to keep people in their roles. They’re excuses. I make them to myself all the time, and it’s clear to me that making these excuses is my biggest mistake (at least it’s my biggest mistake when I’m in a blaming mode). If you’re hanging on to someone who’s not doing the job and making these excuses to allow yourself to keep the person, it’s time to act. Hanging on to these folks is a big reason behind your failure to achieve your goals.