A dismissal for poor performance generally follows the “3-strikes” rule.
Your employee will have had a first written warning and a final written warning and you are now considering a dismissal.
This is assuming that everything has happened in a straight forward linear process, which often is not the case.
Each case will have its own complications and this will determine the process that you need to consider.
Employers need to be careful if there are any medical reasons affecting the performance of the employee as you need to deal with this extremely sensitively.
Employees could potentially use this as a case to bring a potential discrimination claim.
This is not to say that it can’t be done, but it is essential that you have clear medical evidence to support any decision to dismiss fairly.
Proceed with caution if medical issues are present and engage professional advice.