1. 1Cranfield University, Manufacturing Informatics Centre, Cranfield, MK43 0AL, UK
2. 2Loughborough University, Department of Computer Science, Loughborough, LE11 3TU, UK
3. 3Third institution, School of Information Sciences, University of Tampere, Tampere, FIN-33014, Finland
4. 4Slovak Academy of Sciences, Department of Informatics, Institute of Mathematics, Bratislava, Slovak Republic