Closing the Loop on Manufacturing Error-proofing with MES

By Anthony Borges, Marketing Manager, PINpoint Information Systems

Manufacturers of any size are ever seeking ways to improve the efficiency and quality in their product assembly operations; and it is efficiency and quality in manufacturing that quantify the effectiveness of both the physical actions performed on the shop floor, and the caliber of products produced as a result. Considering that quality and efficiency are the life blood of any manufacturing company, closing the loop on error-proofing is not only important but often ignored. All to often manufacturers implement manufacturing execution systems (MES) as an extension of their Enterprise Resource Planning (ERP) system only to realize the MES system they implemented does not actively ‘Execute’ anything.

The assembly line is a chaotic bees nest of activity with both humans and machines trying to work in harmony to complete tasks and produce quality products. The trouble is humans make mistakes, and machines, tools, parts, and devices are prone to fail; creating the recipe for operational inefficiency and poorly made products. Product assembly is further complicated by the nature of humans, i.e. humans can be objective in their decisions, and if driven by pressure (say process step cycle time constraints) may try to cheat the system.

For example, a line worker may be using a fastening assembly tool to fasten a bolt in a vehicle transmission; as they perform the fastening operation they receive a ‘No Good’ or ‘NG’ message from the tool controller since the system detected the specified torque and angle parameters were not met. At this point the line worker would try to remedy or correct the situation by trying to run the tool again, or a third time or more until the system indicates a ‘Good/G’ result. The clear issue in this example is the line worker is able to fix the individual problem she/he is having, and in-turn advance the product (which may be defective) to the next station, and ultimately out of the factory, with no one besides the individual line worker themselves knowing what had happened.

The line worker in the example above was able to make her/his own decision on the ‘quality’ of the fastening operation they performed, and pass the product, without a line supervisor or quality engineer approving it. Further, the error that occurred in the operation was not quantified, i.e. the error may have been on the part of the human action(s) only, or it may have been because of a defective tool, or a defective part. Without this deep level of insight into the problem, a solution cannot be had, and the mistakes will naturally be repeated.

The solution is to introduce a system of full-accountability into your manufacturing operations; to close- the-loop on the chance for any defective products to pass. The method to accomplish the goal is to integrate a software based configurable product with specific capabilities for controlling, enforcing, and documenting all manufacturing processes. An all-encompassing MES system both monitors and controls processes, making it the ultimate error-proofing tool because it is responsible for directing the process steps to assemble the product, and to determine whether they are completed in tolerance or not.

MES systems are needed to keep an eye on both the human, and the tool/device results, as well as to stop them in the event a process step specification is not met. To maximize error-proofing it is most imperative that the MES system both ‘Monitor’ and ‘Control’ the entire assembly process. The MES system must have the capability to halt operations, or stop individual line workers, and turn off all devices or tools associated with the work station and product assembly progress. Only by fully monitoring and controlling the assembly line can the MES system be effective and full-proof in its’ error-proofing operation.    

Fully-monitoring the assembly line starts with first verifying the line worker’s credentials when they login to their ‘SmartScreen’ display at the workstation. Line workers must be qualified to perform the process steps at that particular work station; and they will only be allowed to start or be presented work instructions once the MES system approves it. Once approved the line worker may read the work instructions on the screen and press a button or enter text to acknowledge to the MES system the document was read and understood. At this time a Quality Alert may be presented by the MES, which again requires the line worker to acknowledge the alert was read.

Only after all security, assembly, and quality instructions are seen by the line worker and recognized by the MES as read and understood, does the system allow product assembly to commence, and tools and devices to be turned on. The graphic below (Figure 1) illustrates a typical MES system network whereas all line worker ‘SmartScreens’ and andon communication big screens interconnect to the plant server/MES; any tools or devices on the assembly line connected to the plant network or PLCs connect to the MES system also. The configuration portal is accessed by engineers in the cloud from a website browser on any computer.

Figure 1: workers receive assembly instructions from SmartScreen user interfaces; the MES system monitors and controls their progress, and allows for configurability on-the-fly from a website browser.

By actively managing and controlling the plant floor the MES system greatly mitigates the opportunity for defective products to pass. Even line workers with very little manufacturing assembly experience can be employed and lead by the MES system to produce quality products in a short timeframe. MES systems empower manufacturers to realize a continuous improvement strategy they can work with and live with long-term. PINpoint’s MES system, for example, features a complete toolset of configuration features you can use to create your assembly line and process steps in real-time, and easily from a website browser on any computer, tablet or Smartphone.

It also features production scheduling, plant floor communications, product tracking, and manufacturing reporting tools as well, making it one of the most complete, flexible and cost-effective MES systems to implement and scale up in time as your manufacturing operations grow.

Perhaps most importantly the MES system enables manufacturers to become aware of the problems that exist, which is fundamental because one does not know what one does not know, right? It is the data acquired from manufacturing that defines the action steps required to improve the efficiency and quality of the operations; it is the manufacturing intelligence and business intelligence afforded by the MES system that defines your strategy for continual improvement to close the loop on error-proofing.

PINpoint Information System’s manufacturing execution system (MES) software is designed and tested to ‘Information Technology Infrastructure Library’ (ITIL) standards before any official version release. PINpoint’s andon and MES System software have been developed since 1997 and continue to be evolved and pushed-forward by leading manufacturers.

The software is in use daily around the World in multiple languages by leading manufacturers. Headquartered in Burlington, Ontario, PINpoint services industry internationally from their offices in Canada, the United States, and China. For more information visit: http://pinpointinfo.com/

About the Author

Anthony offers over a decade of manufacturing optimization knowledge, with an aptitude for solving problems which increase manufacturing efficiency. He has successfully provided solutions to various multinational manufacturers involving the latest technology in sensors, laser (detection, measurement, welding, cutting, and marking systems), PLC, machine vision, microscope, and software solutions.