You are the financial manager of a school where some teaching departments are spending more than their budget allowance on materials and others are being frugal and spending less. It is six months into the financial year and you would like to give a warning to the overspenders, but also find out why there are underspenders. Suggest two ways of dealing with this problem, of which one way would probably create friction between yourself and the teachers, while the other would encourage the teachers to work with you in controlling the overall budget for the school.