This is a tricky one - at what point do you need a professional event manager or events management company. It may be (as with our company) that your bar supplier can also assist with the event management. We are lucky to have events personnel that have been on the team of high profile corporate events as well as brand campaigns and festivals (see www.eventexpert.co.uk for more details). This means that you could get the benefits of event management as part of your bar management package. But the events management business is often about specialist suppliers and professional expertise, and often involves organisational and operational skills - so think about you event in terms of what it is you need to achieve and it should be clear whether or not you require a more specialist approach. For example, sustainability may be high on your agenda - in which case you require a team that understands how to acheive this effectively (see www.ecoevents.com)