Machine Vision Inspection Saves the Day when Manual Inspection Fails

Our mighty Machine Vision Inspection team saved a critical production line for an automotive OEM.

True story: we leveraged machine vision inspection to save our customer a whole lot of time, money, and headaches. An automotive OEM was experiencing major shutdowns on a critical fuel injection assembly line. Due to a shortage of inspectors on staff, assembly workers were performing the inspection. But, they were ill-equipped to do so. As a result, they were falling behind on production. Consequently, the OEM was bleeding money.

This inspection process was vital to prevent engine failure. Defective parts could block fuel injectors and cause leaks. So, the tier-one supplier of the part, a long-time customer of ours, asked for a manual sorting quote. However, after reviewing the scope of the project, we recommended that they use machine vision inspection instead. 

Visual Inspection is susceptible to human error.

The visual inspection process in place was time-consuming and complicated. It required a manual gage, a microscope, and a great deal of manual part handling. First, the assembly workers had to look at the inside of the fuel injection component through a microscope (causing additional eye strain) to check for material flaking/delamination. Next, they visually inspected the outside of the part for the same flaws. Last, they had to validate the ID of the part and check the outer width of the part using a manual gage.

It took as many as 6-8 production employees for the full visual inspection! And with each additional touchpoint, the risk of missing a failed part increased. People naturally become fatigued throughout the day. They can also get distracted, emotional, and make poor decisions. Again, this work is critical to assembly. Material separation in a fuel injection system can create serious performance failures. Oversized and undersized components can also cause errors in assembly and engine failures.

Bottom line: their critical inspection process was putting extra strain on their assembly workers, costing tons of money, and preventing them from hitting production targets. They needed a reliable, simple solution–ASAP.

This is how we turned a Visual Inspection nightmare into a Quality Win.

Once we had a full understanding of the challenges, we recreated their process at our facility. Within a few days, Witness Inspection had taken over inspections from the OEM. We quickly replenished their inventory and caught up to the demand of 60,000 pieces per day. Creating appropriate work instructions, gage studies, and quality documentation, we were able to smooth out the process.

At the same time, we had our Machine Vision Inspection team investigating an automated solution. We knew this could reduce costs and improve overall quality. To do that, we asked the OEM to provide defective parts for analysis. This helped us program the machine to reject parts for every possible defect. Not just gross damaged parts, but also the finite failures undetectable by the naked eye.

First, we reviewed parts that failed the gage inspection–the most common failure. By measuring the inner and outer dimensions (ID and OD), the gage checked the roundness of the part. Small, microscopic dents and dings were making some of the parts less round. So, we conducted an FMEA (Failure Modes and Effects Analysis) to understand what was happening. Results showed these defects sometimes happened during stamping, but mostly during the 3rd party cleaning process. 

ID lamination was causing the next highest failure. Through multiple studies and trials, our engineers designed an automated solution to detect it. We used 3 individual machine vision cameras, to detect ID lamination. Setting each camera to a specific focal length allowed us to catch all of these defects. For OD lamination, we used a pericentric lens to inspect the part as it rotated 360 degrees. We ran pulsation trials with the customer to prove the failure of the part within the assembly.

After that, we used all the data we gathered to prove our automated inspection process.

Staggering results show that Machine Vision Inspection is the way to go.

Our automated inspection solution saved our customer and their customer a ton of time, money, and headaches. In the end, it completely eliminated the need for a visual inspection process. Our machine vision inspection expertise saved them over 300 labor hours PER WEEK. Moreover, the new program saved them $250,000 annually. That’s a whopping 70% savings!

In conclusion, Machine Vision Inspection is more accurate and less costly. Most importantly, it saves a ton of labor hours. And with an ever-increasing labor shortage, can you afford to NOT automate?