I was writing a bullying and harassment policy and to update myself on the topic, did some research on the subject. It's always useful to revisit the theories about bullying in a more in depth way. By way of a refresher , here are some things for you to think about:
When a complaint is investigated and the finding is that communications should have been better, don't conclude that this is just down to poor management. Withholding information is a form of bullying. Poor management is a form of bullying. Don't protect the bully, even if the person is a senior manager. A poor performer should be able to be told about his/her poor performance without feeling bullied. So make the link between your performance management practices and anti-bullying training. Appreciate also that bullying is caused by the perpetrator's own feelings of inadequacy. So put in the support mechanism, not just for the person claiming to be bullied , but also for the person accused of bullying.