First check your Grievance Policy.
Most complaints can be dealt with informally, so check this route out first.
Serious complaints will need to be handled formally from the outset.
Serious complaints may involve allegations of:
These are just a few examples.
Follow our AIMLA model:-
1) Acknowledge the complaint
2) Investigate the complaint, gather evidence
3) Meet the employee to discuss the evidence
4) Let them know in a letter giving your decision and the right to appeal
5) Appeal - deal with this if it occurs