All employees must be able to perform the tasks that are essential to the job. An employee who is not able to perform the ‘inherent’ or genuine and reasonable requirements of the job may be terminated lawfully.
It is very important to identify what are essential or inherent tasks. If there is a particular way of doing the job which you are not able to do, you should be allowed to carry out your duties in a different way if doing so will deliver the same outcome.
For example if an employee is required to use a computer to write correspondence, using the computer is an essential task, but using a keyboard is not. So a person who may not have the fine motor skills to use the keyboard can use a voice activated computer and still be able to write the required correspondence.
However if you are hired as a sales person and need to travel around country areas and demonstrate how to operate a machine, that travel is an inherent part of your job and, depending on circumstances, driving may be an essential requirement. If you lose or do not have a licence to drive because of a disability, then you are not able to perform an inherent requirement of the job