Automated Scheduling, Optimisation and Planning Group, School of Computer Science, University of Nottingham, Nottingham, NG8 1BB, UK.|Automated Scheduling, Optimisation and Planning Group, School of Computer Science, University of Nottingham, Nottingham, NG8 1BB, UK.|Automated Scheduling, Optimisation and Planning Group, School of Computer Science, University of Nottingham, Nottingham, NG8 1BB, UK.|Automated Scheduling, Optimisation and Planning Group, School of Computer Science, University of Nottingham, Nottingham, NG8 1BB, UK.