An approach for the assessment of safety risks in automated mobile workmachine systems: Dissertation

Needs to improve productivity and cost efficiency are driving the development in industrial sectors using mobile work-machines towards automated work-machine systems and production process control.The shift from manually operated mobile work machines toward automated mobile work-machine systems takes machinery-safety considerations to a new, system safety, level. New safety concerns are associated with automation-related threats and possible unexpected hazardous events. Regardless of the extensive international standardisation efforts in machinery safety, there are not yet safety-engineering or risk-assessment guidelines specific to complex automated mobile workmachine systems. The aim of this study has been to provide new information on how the riskanalysis methods in current use can be utilised for reaching the system-safety objectives and to increase the quality and effectiveness of safety-engineering work. The main goal of this study was a practical approach for system-level safety-risk assessment in automated mobile work-machine systems. Constructive research approach has been applied for the construction of the risk assessment approach. Evaluation of the usefulness of the overall approach and risk analysis methods has been done following the qualitative case-study research methods. The empirical research material consists of four case project documentation, interview results and observations. The result of the study is a new three-level approach for the assessment of safety risks. The results of the study show that the three-level approach to risk assessment is applicable for automated mobile work-machine systems and the selected methods are applicable for system-level hazard identification and risk analysis. The approach and the methods have been adopted in case companies. The developed approach integrates key elements from system safety, machinery safety and industrial safety engineering practices. The case-study research results provide new valuable information and experiences in how the riskidentification and risk-estimation methods were utilised in the case projects in various phases of the system life cycle. The results can be utilised among mobile work-machine manufacturers, system suppliers, end users of the machinery systems, and safety experts.