Mental Load And Management Strategy Of Light Assembly Operators Considering Time Pressure And Task Complexity

With the advancement of science and technology and the development of industry,the nature of the work performed by workers on the production site of the manufacturing industry has also undergone significant changes.The job task's demand for the operator has shifted from the physical labor demand mainly to labor output to the psychological cognition demand.In particular,light assembly operations have the characteristics of small parts size and low degree of differentiation.Operators have relatively high demand for mental cognitive resources such as operator attention and engagement when repeating parts identification,picking,positioning and assembly,and affected by time pressure and other factors,it will cause attention resource transfer,decreased engagement and other phenomena,resulting in increased probability of human errors and safety accidents.At the same time,the complexity of different tasks will also have an impact on the mental load of the production site staff.The traditional production organization method pays too much attention to external information such as resource allocation and technical investment in the production process,and ignores the changes in the mental load status of the individual's own attention,engagement,and cognitive resources during the production process,resulting in problems such as unstable assembly time of the operator and high error rate,which is not conducive to the improvement of production efficiency and the optimization of production management.Therefore,it is necessary to carry out research on the mental load of the operator in light assembly operations,in-depth study of the effect of the mental load of the operator on production efficiency and the neuroscience mechanism behind the impact,and to propose a production organization strategy based on the mental load of the operator,which has important research value for improving the production efficiency of the enterprise.Therefore,this research is based on enterprise research and consulting relevant literature,assembling with Lego models to simulate light assembly operations such as electronic products,instruments,control devices,etc.Designed LEGO model to simulate light assembly experiments with time pressure(none;low;high)and task complexity(simple;complex),and used NIRS and EEG equipment to monitor changes in the concentration of oxygenated hemoglobin in the prefrontal lobe of the operator's brain and the changes in brain wave signals in F3,Fz and other brain regions in real time.After the task is completed,the subjects are asked to fill out the NASA-TLX scale.Based on the experiment,comprehensively analyze the operator's assembly time,assembly error rate and other behavior data and O2 Hb concentration,Alpha wave,Theta wave,cognitive state and other neurophysiological data,and find that there are significant effects between time pressure,task complexity and attention resource requirements,engagement,workload,and cognitive resources.The results show that time pressure leads to an increase in the workload and cognitive resource requirements of the operator,which promotes the engagement of the operator who performs simple tasks,improves the performance of the operation,and also causes the attention shift,mental load overload,and performance decline for operators who performs complex tasks.The research reveals the intrinsic influence mechanism between the mental load and operation performance of the operator in light assembly operations,and proves the assumptions about mental resource allocation,working memory storage,and self-regulation in the limited resource theory,behavioral regulation theory,and multi-resource theory.On the basis of the above,according to different production task needs,the priority order of different task arrangements is given,and the production management strategy that considers the heterogeneity of the operator(Gender differences and perceived differences),and the job rotation system and the rest system are proposed,and pay attention to the operator's emotions,improve individual abilities,improve the production environment and other management strategies and suggestions in the production process.With a view to guiding enterprises to comprehensively consider the human body status and production information to optimize production management,pay attention to the impact of human mental load factors on production efficiency,increase the emphasis on human-centered role,humanize to improve production efficiency,achieve sustainable and efficient production and the long-term development of enterprises.