Production-failures.Avoid rather than Repair them.SOLUTIONS with Effective, Practical Advice
Loss of material and money, loss of productive time, production of scrap, need for repair, supply delay, loss of customer confidence, are some of the immediate effects of any serious disorder to production plans. (Sponsored Links) While regular workers are suddenly out of their work, and new productive activities have to be made up for them in a hurry, other people must be brought in to investigate the hindrance of Production-failures, and find out in the shortest time a suitable way to resume correct production. In a different page on Welding Failures, we examined the occurrence of failures in service, where the core reason for the accident has to be determined for ascertaining responsibilities and for finding ways to avoid such events in the future. In that page we wrote that "Regarding Production-failures, the inability of a test piece to stand up to mechanical requirements, or of a workpiece to meet nondestructive inspection demands, should be called avoidable defective conditions, and should be addressed with a different approach". Notwithstanding the pressure from production management, no shortcuts are generally available, and a thorough investigation of Production-failures should be called for, possibly conducted by persons with knowledge and experience of the processes involved. The task of whoever is in charge of investigating Production-failures is to describe them fully and to check step by step all operations stages, to isolate those introducing the non conformances. A review of the most common Welding Defects may be useful at this stage.Further information on this topic may be found in the online links listed in our Mid December 2007 Bulletin, available by clicking on Additional nondestructive testing may be required, to further characterize the discrepancies from requirements and for looking for Production-failures origins. Among these, all unacceptable discontinuities described in engineering documents must be investigated, by looking in depth at the causes generating them. In particular cracking, a frequent occurrence of Production-failures, may have many origins that should all be addressed by a complete metallurgical examination that uses all needed suitable means. See in this context Weld Cracking and Stress Corrosion Cracking. In the past, a short note on Welding Failures Investigations, intending specifically Production-failures, was published (2) in Issue 66 of Practical Welding Letter for February 2009. Click on PWL#066 to see it. A few checks should be made to collect information on Production-failures and to look for suspicious signs that might help in finding out if any obvious causes contributed to the mishap. A simple analysis may hint at what went wrong and suggest how to overcome the hindrances. Beware of changes. If you know that until some time before, there were no hints of difficulties, and manufacturing went on normally without Production-failures, then look for anything, including negligible details, that may have since changed. Sometimes, in the quest for small savings in materials or time, unjustified short cuts are initiated by persons who may have large experience in other sectors, not necessarily in the Production-failures environment. Any apparently minor change should be questioned: about suppliers, materials, consumables, equipment, routine maintenance, tools, fixtures, workers, helpers, spares, parameters, location in the shop, time of the day, weather, temperature and many other details not included in this partial list. Don't overlook anything at this stage. If you find a difference, don't dismiss it as unimportant. Be especially suspicious with material changes, even if nominally the new ones (possibly cheaper) should be exactly the same as those used before. Then check the equipment working condition. Maintenance people should see worn out or partly damaged items that must be replaced to avoid Production-failures. If measuring instruments were not calibrated recently, they should be calibrated now, otherwise there is no way to know if the applied parameters are correct. Welding Procedure Specifications should be checked or established if missing, to have all details written and fixed. No essential preparation steps or checks should be skipped, because quality and Production-failures depend on them. New production, never attempted before, should be preceded by process development and implemented while collecting all data and results to validate equipment and parameters. When investigating Production-failures, documents recording previous experience could be instrumental in finding what went wrong. For this reason, if not for other Quality Assurance obligations, they should be initiated and collected regularly. In particular receiving inspection certificates and test reports, heat treatment logs, equipment regular maintenance records, welding documents like WPS (Welding Procedure Specifications) and PQR (Process Qualification Records), welders' certifications, and testing and inspection reports may have much importance in helping investigations of Production-failures. In conclusion one must remember that in production the successful performance is limited to a narrow window for each one of a great number of determining factors. Any small deviation from what was determined to be the best practice, may shatter the good results. However difficult, it is much easier to keep constantly all parameters correct, than being compelled to look for whatever caused production failures, if anybody wilfully or negligently missed essential steps of the process, possibly in the vain hope of sparing toil or of gaining time. Any questions or comments or feedback? Write them down and send them to us by e-mail. Click on the Contact Us button in the NavBar at top left of every page.
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