ABSTRACT
In life science process laboratories, common procedures often include calibration of systems for amino acid concentration measurement. Such procedures involve lab preparation, pipetting, automated systems programming, and data analysis. These activities may pose high levels of stress for technicians and can lead to excessive mental fatigue and errors. There is a need to empirically define an acceptable level of workload (or an overload threshold) for technicians as a basis for determining appropriate distributions of work tasks among operators or work-rest schedules. We conducted a field investigation at the Center for Life Science Automation (CELISCA) at the University of Rostock (Germany). Three professional technicians completed a series of tasks as part of an amino acid calibration process. Task completion time and technician perceived workload ratings using the NASA Task Load Index (TLX) were collected. Results revealed activity types and task exposure time to be influential in perceived workload. Mental and temporal demand components of workload were found to be significant 72in overall workload across task types. A composite stress index (CSI) was prototyped incorporating both cognitive and temporal demand ratings and task exposure time. An inspection of the distribution of CSI values suggested the 67th percentile to be a potential workload overload threshold for rescheduling of technicians across processes and among activity types in order to prevent mental fatigue and errors.
