Brittleness Assessment And Preventive Maintenance Decision Method For Tandem Production Line

Aiming at the production capacity fluctuation and downtime caused by random failure of production line,this paper studied the evaluation method of production line brittleness considering failure time window,and put forward the preventive maintenance decision-making method of production line equipment.Specifically,by analyzing the temporal and spatial properties of the production line caused by random faults,the time window was modeled,the equipment failure rate function and the production line capacity loss model were determined,and the transient/steady-state brittleness assessment model was constructed.Based on the consideration of the production line capacity loss caused by random failure,combined with the brittleness assessment,the preventive maintenance decision of production line equipment was studied.Brittleness evaluation model and maintenance decision method were applied to mobile phone assembly line.The validity and rationality of the model and method were verified.The specific research contents of this paper were as follows:Firstly,the temporal and spatial properties of production line brittleness were analyzed,the concept of production line failure time window was put forward,and then the transient/steady brittleness evaluation model of production line was put forward.The spatial attribute caused by the location of fault machine and bottleneck machine and the time attribute caused by the duration of fault were analyzed.After that,the weibull distribution function was used to fit the unit failure model,and the equipment failure rate function was determined.Based on the steady state analysis of buffer occupied state,a quantitative evaluation model of steady state brittleness of production line was established.Secondly,the method of preventive maintenance and replacement maintenance of production line equipment based on reliability and cost was proposed.In order to accurately describe the change of failure rate in the operation and maintenance process of mechanical equipment,the decline factor of service age and deterioration factor of failure rate were introduced in this paper to establish a more reasonable mathematical model of failure rate evolution of equipment.Considering preventive maintenance and shutdown cost,unexpected fault maintenance and shutdown cost,taking equipment reliability as constraint condition and the lowest maintenance cost per unit time as solution target,a single-equipment preventive maintenance strategy model was constructed,and a preventive maintenance interval solving algorithm was developed.Finally,brittleness analysis method and preventive maintenance decision met hod were applied to mobile phone assembly line.Based on Demo3 D software simulation,the validity and rationality of the system's steady-state brittleness and transient brittleness were verified.Then,the model of single equipment preventive maintenance decisionmaking method of mobile phone assembly line was constructed,and the preventive maintenance interval and replacement time of equipment were solved,so as to develop a scientific,reasonable and effective preventive maintenance plan.