There have been some good ideas already, but I don't think you can have a World Class department unless you can create one that enjoys working together. You all need to be prepared to trust each other; to share successes and failures; to ask for and offer help. You want a team that is willing to innovate, not for the sake of it but to find what works, what can be adapted to make it work and what can be quietly dropped. You need to be fair, not dumping the worse classes on the most junior people but sharing out classes according to individuals' abilities and encouraging them to develop new skills so that they can have more variety of teaching. Early on you may upset a few people, but after that, it can become a department in whcih people want to work, reducing staff turnover. Once that happens, you can really think about seeing improvement year after year.