Bill Bellows, associate fellow at United Technologies’ Pratt & Whitney Rocketdyne division and LMJ’s editorial board member, shares a brief proposal for the integrated use of Micro and Macro System Model.

What if every professional firefighter in the world followed their country’s firefighting orders? In the United States, these documents are known as the 10 Standard Firefighting Orders and 18 Watch Out Situations. Would there ever be another firefighting injury? Or, in a manufacturing plant, what if standard planning and processes were followed by every operator, to the letter? Would defect-free parts be produced time and again? Would the resulting parts be identical and then “fit” into a sub-assembly and the many sub-assemblies into an airplane, smart phone, or fire truck?

The planning model of interchangeable parts, with major contribution often given to Honore Blanc, who lived in France in the late 1700s, offers such a vision, with an outcome of products, processes, and services that “work” (as planned), including zero fight fighting fatalities.

The American System of Manufacturing followed shortly thereafter when Thomas Jefferson’s implementation vision was shared with Eli Whitney, leading to the first-ever contract with the US Congress for a product made with interchangeable parts.

Such a simple design model is founded upon assumptions that include no variation in the interpretation of the standard processes and no variation in how the steps are followed, leading to no variation in parts and, further along, no variation in sub-assembly fit and no variation in system performance.

For firefighters, add the belief that reaction times are faster than changes in fire conditions. Other than constant daily reminders of the existence of variation, from non-identical twins to non-identical snowflakes to finite and variable reaction times, one might lapse and believe such a Utopian tale of a digital universe. For clarity, such a system could be referred to as a Macro System Model, which, like all models, can be said to be wrong, but, at times, extremely useful. As a fitting complement, consider the existence of a Micro System Model, in which variation in parts, fits, and performance is acknowledged, monitored, and maintained, if not purposely reduced or expanded. In such a model, parts are “parts of” something larger and then again so, with the Macro System Model offering an ever-useful frame of reference for views from a distance.

In my industry experience over the past 25 years, I have found both the Macro and Micro System Models to be operating invisibly, leading to all too frequent consternation and problems, let alone failed solutions. With great consistency, I am also reminded of quality as defined by the classic model of “conformance to requirements”, with little, if no regard for the quality of how well parts are integrated and a realisation that interchangeability is always relative and never absolute. Such is the prevailing thinking of quality in the communities of practice of six sigma quality and lean, with rare exception.

Perhaps if our organisations delivered parts that literally flew in close formation, never touching one another, would there be a need to focus on the quality of parts taken separately? If, however, the parts are part of something bigger, such as a steering wheel of an automobile is part of a steering system or a turbo pump is part of a rocket engine, would the relationship between the parts be a more appropriate focus of attention, rather than the parts taken separately? If so, how the requirements are met would be a focus of great interest, implying a visible causal link between how requirements are met and how parts are integrated.

Such awareness would surely lead to advances in systems engineering and systems practice. Lacking a Micro System consciousness of the existence and location of variation for a given set of requirements, organisations are forever trapped in a world of parts, with the belief that all parts that meet requirements are not only good, but also equally good. If so, conversations about how requirements are met would be of little value, hence considered waste.

Much the same for how many resources (people, money, equipment, time, etc.) are allocated within organisations on parts that are good and arrive on time, a favourite question, for which the answer is almost always ZERO! As with the ability to categorise nonconformances by type and timing, yet not significantly reduce their occurrences and cost structure, here lies another reminder of the invisible influence of the Macro System model in daily practice. And, should defectfree parts and tasks be achieved, could improvement be justified once requirements are met?

Unknowingly, a Macro System viewpoint creates both personal and organisational blind spots that deny opportunities for continuous improvement if one was to adopt a Micro System Model and seek gains associated with managing variation in how requirements are met, not stopping at zero defects. I’m not the only one to see gold in these streams, yet, as judged by the language and focus, lean six sigma efforts are not overly aware of the mining opportunities herein. Instead, these conversations lead to the elimination of muda and non-value added tasks and miss the golden opportunities of a Micro System view.

Interestingly, the model of Quality Loss defined by Genichi Taguchi in his pioneering focus on the quality of relationships, not parts, was adopted by Toyota in the 1950s and is still in use today, only visible to those trained to see such Micro System behaviors. To those who choose to embrace a Micro System viewpoint, as one does at home when aiming for a target dimension when defining the required length of a part of a home project (and not merely conforming to the requirements of a mechanistically defined tolerance), one may perceive that the success of the Toyota Production System cannot be solely explained by the existence of a Macro System Model, with its steadfast belief in “conformance to requirements” and “parts that are good are equally good”.

Those who can peer past this model and juxtapose it with a Micro System viewpoint will perceive the opportunities for returns by making good parts better, limited only by the achievement of gains that outweigh the investments. In doing so, organisations will realise the limitless opportunities for teamwork that are associated with an acknowledgement of interdependence, not the limitations of independence that a Macro System Model is built upon. I have been fortunate to see these results first-hand on many occasions, yet do not see their accounts explained often enough by the ongoing research in the lean six sigma communities in which I have participated.

This comment piece is offered to provoke an exceptional value proposition behind exploring opportunities for investment in parts that are not equally good, for the existence of variation in life assures us that modeling the performance of an assembly of good parts and sub-assemblies as “fitting” and the resulting product to “working” defines a world without variation.

As organisations awaken to the interdependence of parts and the profit potential of teamwork, more and more customers will benefit from thinking about Macro and Micro System Models in the way that Toyota’s customers have grown to expect.