While a successful recruitment is a game changer and the most important achievement for any manager, unfortunately it does not work out every time, even if you have done everything to make sure this would be a successful hiring.
When you know that you have hired the wrong person, the worst possible decision is to keep this person because “you need someone to do the job”.
This is so wrong… this is such a huge and costly mistakes that we have all done. This is so wrong because this is not working, you think this person will do the job that you have no time to do, so you need this person, but you are actually digging your own grave as this person is going to accumulate mistakes that it will take you so long to clean up after.
The old adage that it is better to be single than in a wrong relationship applies extremely well at work. I promise it is better to have no one doing the job, than having the wrong person doing it. Every additional day when you keep the wrong person, you accumulate more issues, problems that will take you 10 times more effort to clean after. An IT developer will generate bugs that you will discover in 6 months and then you will have to rebuild the entire software, an accountant will record transactions in the wrong accounts and when you will close your books at the end of the year it will not work and it will take you a big effort to understand why and then to correct this, a sales rep will create frustrations with a client and you will find out only at the end of the contract when the client will not renew or the cost of rebuilding the trust will be huge. Whatever the job / role we should never keep someone who is the wrong person for the job.
Of course you can only know if the person is the wrong person for the job once you have done everything possible to help the person with training, coaching, mentoring etc… subject to ourselves being good managers. The point is not to give up as soon as we have a doubt, the point is that once we know it is not going to work then we should not wait, we should not lie to ourselves and take the difficult decision (and execute the decision).
Keeping someone who is the wrong person for a job is a huge and costly mistake for oneself, for the team, for the organization and even for the person herself.