The term Genchi Genbutsu literally translates from Japanese as ‘going to the source’. In order to solve the problem within an automotive industry or any other related field, the best way to understand the root cause of the problem is to physically go to the source or Gemba (place of occurrence) to analyze the root cause. Without proper root cause, it is practically impossible to come up with a proper and permanent fix to the problem. We must analyze the point of occurrence in order to get as much clues as possible. A proper diagnosis cannot be made if we are not physically present at the source. For example a problem occurring at an assembly plant cannot be properly diagnosed over the phone. There are many factors that contribute to incorrect measures of knowledge transfer if the diagnosis is tried over the phone or by email.
Just like in the 8D problem solving concept, after visiting Gemba, first order of business is to take immediate interim containment action, then work on a root cause. After these steps, permanent corrective actions can be verified and validated. There should also be a plan in place to prevent reoccurrence of the problem. This is the permanent countermeasure.
In most cases vehicle recalls occur, when during the time of durability testing a failure is either ignored as a onetime occurrence, or not properly diagnosed. Vehicle recalls could be largely avoided if we put in place 100% quality check during, and after the development phase. This has to take place at the suppliers end. But the problem is that the vehicle manufacturers do not completely apply the Quality Management System (QMS) towards the supplier. Yes off course, during the time of initial audit these problems are discussed and highlighted to the supplier, and an audit report is generated based on the New Supplier Audit (NSA) criteria, giving the supplier a green, yellow or red status, but do we really follow up with a second audit to see if the supplier has really corrected these problems?
Most recalls occur with the product or component failure produced by the supplier. In some cases vehicle design and vehicle dynamics are also to blame. Remember the case of disintegrating Firestone tyres on the Explorer, where Ford switched from solid rear axles to backward facing independent suspension lower control arms to curb any more suspicion on their design (yet the real root cause is still unknown, whether it was the tyre tread quality, low air pressure or due to the design of their solid axles). A lot of vehicles have solid axles but we have not seen similar failures in them, so I personally think it is a hard pressed issue to just blame it on the vehicle’s rear solid axle design alone.
The question to ask is why did a certain product fail? Obviously we demanded and saw all duty cycle and durability testing reports made by the supplier, then where was the escape point? In my experience I have noticed two main factors, the first being that the supplier has used their own internal testing lab to conduct duty cycle on the parts, second being that the supplier has sub-contracted some components such as nuts and screws or materials to another supplier which is not properly vetted by our supplier. In order to resolve the second problem, we must also conduct a full facility audit of any sub-contracted suppliers.
Another root cause for sub standard components is that the supplier changed the material specifications during the lifecycle of the product without notifying the manufacturer. It must be strictly enforced that any change in material after Product Part Approval Process (PPAP) must be communicated with details to the manufacturer, and prior approval must be needed from
the design engineer through an Engineering Change Form (ECR).
In many cases when the supplier changes the material specs without notifying the manufacturer, we end up making a Deviation form just to keep the production line running. Deviation forms should in all cases be avoided. It is not a good practice. If the supplier is planning any change, a new PPAP must be conducted, otherwise no change should be allowed. This practice will greatly reduce product recalls in the automotive industry.
Therefore, Genchi Genbutsu plays a major role in how we resolve problems. If we are vigilant during the time of new supplier audit, and duty cycle of the product knowing all SAE testing standards, we can to a great extent avoid even using Genchi Genbutsu in the product recall process. However, in the manufacturing assembly plant where the process is constantly evolving, Genchi Genbutsu should be used by all to conduct and correctly solve the problems the first time around.