✔ 最佳答案
I don't know what details of your employee, so, just can give you a sample below. Hope this helps.
Re:Poor Working Performance and Unpunctuality
This serves as the last warning regarding your poor working performance and unpunctuality. Despite our repeatedly verbal and written warning, no improvement has been made. Due to the tight working schedule in our department, you should come to work on time, if you are unable to report duty, you should notify your supervisor close to your starting time as possible (copy of attendance record enclosed).
In order to maintain good discipline within department, dismissal action surely to be followed if no improvement in future.