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I’ve always been amazed and impressed by the knowledge and problem solving capability of plant-floor workers. Skilled and knowledgeable tradespersons and operators really know what’s going on at a site. And they’re an extremely valuable resource in our quest to run reliable and safe operations. Unfortunately, I’ve been equally amazed, but unimpressed, by managers and engineers who don’t leverage this resource.

Too many organizations only employ tradespersons and operators “from the neck down,” and fail to take advantage of experience, knowledge, and creativity of plant-floor teams. During root-cause analysis (RCA) events, I’ve often (too often, that is) heard from operators and maintainers that they had anticipated the problem, but the head office simply didn’t ask or hadn’t paid attention when they raised warnings.

Big problems that warrant RCA are usually the byproduct of small problems that we didn’t attend to when we could have and should have. The answer is to instill a “why-why” culture that actively engages all that knowledge, experience, and creativity that plant-floor personnel bring to the table on a daily basis to prevent large events that are disruptive and demand RCA from happening.

A why-why culture is based upon why-why analysis, which is sometimes referred to as five-why analysis, apparent-cause analysis (ACA), or shallow-cause analysis (SCA). Make no mistake, these scaled down cause-analysis processes are no replacement for RCA when solving significant or complex problems. When, however, they’re routinely practiced on the plant floor, every hour of every day, in a why-why culture, these tools can reduce the number of small situations that could compound and evolve into major problems. 

Five-why analysis was originally created by Sakichi Toyoda (Toyota) as a tool to drive Kaizen (continuous improvement) as a part of the Toyota Production System (TPS). In essence, one asks the question five times in succession to move from a failure mode or effect (what) to the failure cause (why). Of course, one must have a reasonable understanding of the mechanism (how) to bridge the gap between the failure effect and its cause. I prefer to call this process “why-why analysis” because, in my experience, some problems require asking “why” seven times to reach a satisfying solution, while other problems can be solved with three “whys.” The point, though, is the same.

Unlike five-why or why-why analysis, which apply linear logic to get from an observed effect to its cause, RCA is a more wholistic process. When conducting RCA, one starts with the universe of all possible root causes. (The failure cause taxonomy defined in the freely available DOE NE 1004 standard guide for conducing root cause analysis is my starting point). With the universe of all possible root causes, the analysis team systematically eliminates causal factors that they know did NOT contribute to the present failure. This leaves a manageable (it is hoped) remaining set of failure causes that were known to contribute to the present event or that can’t be reasonably excluded.

In most instances, “event” is the operative word. In in my opinion, that’s a problem. We typically employ RCA, why-why analysis as events in response to undesirable situations related to reliability, safety and/or environmental performance. But why must the process be event-based? Why can’t it be engrained in the culture, as was intended by Sakichi Toyoda and Taichi Ohno (the mastermind of TPS)? Their vision was to move cause analysis to the plant floor and engage the experience, knowledge, and creativity of operators and tradespeople as a matter of routine.

For example, whenever an operator conducts an inspection route and identifies an anomaly, there’s an opportunity for why-why analysis. Likewise, whenever a tradesperson completes a corrective maintenance task, there’s an opportunity for why-why analysis. And whenever a tradesperson encounters a job that’s difficult to complete due to lack of access, inadequate work instructions, incomplete tools specification, and/or wrong or missing parts on the bill of materials (BOM), there’s an opportunity for a why-why analysis. The objective is to solve small problems and make incremental improvements every hour of every day so we can prevent large disruptive events from getting off the ground.

Are you only employing plant-floor team members from neck down? If so, implement a why-why culture and begin harvesting the benefits of their invaluable background and know-how. The plant will be safer and more reliable and its plant-floor team members will feel appreciated for the opportunity to contribute.TRR

Drew Troyer has 30 years of experience in the RAM arena. Currently a Principal with T.A. Cook Consultants, he was a Co-founder and former CEO of Noria Corporation. A trusted advisor to a global blue chip client base, this industry veteran has authored or co-authored more than 250 books, chapters, course books, articles, and technical papers and is popular keynote and technical speaker at conferences around the world. Drew is a Certified Reliability Engineer (CRE), Certified Maintenance & Reliability Professional (CMRP), holds B.S. and M.B.A. degrees, and is Master’s degree candidate in Environmental Sustainability at Harvard University. Contact him directly at 512-800-6031 or dtroyer@theramreview.com.

Tags: reliability, availability, maintenance, RAM, five-why analysis, Toyota Production System, TPS, apparent-cause analysis, shallow-cause analysis, root-cause analysis, RCA