Where to improve in human-in-the-loop tele-operated maintenance? A phased task analysis based on video data of maintenance at JET

For the planned teleoperated maintenance of the experimental fusion plant ITER the time performance will be critical. Telemanipulated task execution is however characterised by long execution times compared to similar tasks performed hands-on. There is little quantitative research on task performance of telemanipulated maintenance available to give insight into most effective areas for improvement. In this paper a detailed analysis of real world remote maintenance at fusion plant JET is performed with the aim to: i) identify bottlenecks in task completion time and ii) quantify the room for potential improvement. Video recordings of the installation of 50 tiles executed by the three official master-slave operators were analysed. The task execution was characterised by a large variation in time performance, between but also within operators. Reduction of this variation could theoretically result in time reduction up to 41%. Recurring tasks like 'rough/fine approach' and 'retreat' covered more than 50% of the total task completion time and were identified as most promising for further improvement. The results will be the base for further research on operator assistance with augmented visual or haptic guidance.