1. We-B Centre, School of Management Information Systems, Edith Cowan University, Churchlands, Perth WA 6018 Australia
2. Department of Information Systems and Computing, Information Systems Evaluation and Integration Network Group, Brunel University, Uxbridge, Middlesex UB8 3PH United Kingdom
3. Off-highway Plant and Equipment Research Centre (OPERC), Department of Civil and Building Engineering, Loughborough University, Loughborough, Leicestershire LE11 3TU United Kingdom