Testimonials
Linking MES and SPC ensures consistent Product Quality!
Traditionally, fastener quality has been maintained by using process monitoring systems on all production machines, and complemented by regular statistical dimensional inspections (SPC). Around 900 operator SPC inspections are carried out on a typical day at WSH. “Our main problem in the past has been that the SPC system was expecting a new SPC inspection after the prescribed interval, although the machine may not have produced over the entire time frame” recalls Dirk Heles, Quality Manager at WSH. “The “inspection-due” prompt generated by our SPCsystem was often not synchronized with the reality on the machine nor was it visible to the operator working on one of his machines. Hence, operators were not sure when the next inspection was really due. Other events such as shift changes, tool breakages or change-overs were causing further irregularities in the inspection intervals”. The final solution was to link MES and SPC using the SK machine terminals and SK-go! system.Now, the inspection frequency is determined by true ® machine running time, and if any required inspections are not carried out in the allowed time frame, the respective machine will be automatically stopped!
MES controls inspection intervals
Missed inspections and out-of-tolerance values cause the machine to stop
When the current inspection interval has elapsed, the machine terminal shows the message “SPC inspection due”. The operator now has a preset time frame within which he needs to complete the next SPC measurements. “When the allowed time frame has elapsed without seeing a valid SPC inspection, the machine is stopped immediately“ describes Dirk Heles of the stringent quality insurance procedure implemented at WSH. “The same stoppage occurs when the measured dimensions are outside of the described tolerances.The machine is only released for production after a new inspection with good results has been made, and the MES program has received confirmation from the SPC-system.”
Monitored inspection intervals with comprehensive documentation
“We now can easily prove, during the regular audits, that 100% of the inspections were performed as prescribed” explains Dirk Heles of the significant advantage of the installed package. “The SK-go! system ® gives us a graph for each produced job showing the stop/go chart of the machine and the times when SPC inspections were performed. This addresses any questioning that may arise from auditors asking about inspection interval delays caused by machine downtime”.
Expanding the use of data networking
WSH is making further use of the available data networking features to further improve product quality. SK-go! has already been expanded with the plant ® maintenance module to improve machine availability and function. Another step includes the introduction of the PTO module which manages full documentation and archiving of all relevant process data. “Our customers' audits are already getting good ratings due to our integral quality assurance system!” smiles Dirk Heles.
