I'm having a minor issue with a member of my team and it is really, really annoying me. We've worked together for a while now and I have a great deal of respect for their way of working. However, book scrutinies, observations, discussions, department meetings, moderation and a whole bunch of other stuff keeps turning up the fact that things that I have directed my department to do are not being done. For example - marking. One of our biggest issues has historically been that there's a lack of consistency across teachers in terms of frequency, language used, advice given etc. so I introduced a fairly formulaic marking system which was designed to reduce time taken for marking and ensure that all students got the same diet regardless of their teacher. I did also say that if individuals wanted to, they could add things to the marking system to personalise it but we all had to do the first bit. Everyone understood; everyone was on board. Except one of them just simply doesn't do it. I'll have a word and they have an excuse and promise to fix it. Next time, still not done. I go back and have a firmer word. They say they didn't understand or they don't agree with the decision I've made or don't understand my reasoning so I go through it again. Then we have a school-wide scrutiny or an external inspector will come in and hey presto, lack of consistency! I'm getting very tired of constantly being held to account for someone who quietly, politely but persistently doesn't do what they're asked to do. It's not that they're not doing things but that they continually do things their own way and I keep getting b****ked for lack of consistency. My line manager is aware and we're in the process of making it more formal. So my question is - how do you deal with members of your department who quietly but constantly do things their own way even when you've asked them to do things slightly differently for the sake of helping the department improve?