| Both sides previous revisionPrevious revisionNext revision | Previous revision |
| articles:crosbys_church_of_zero_defects [2023/01/22 16:50] – [Why "Zero Defects" is a flawed concept] rrandall | articles:crosbys_church_of_zero_defects [2024/02/05 21:05] (current) – [Why "Zero Defects" is a flawed concept] rrandall |
|---|
| ===== Crosby's Church of "Zero Defects" ===== | ===== Crosby's Church of "Zero Defects" ===== |
| ~~NOTOC~~ | ~~NOTOC~~ |
| It is surprising that a common topic of debate among quality professionals today is whether the "Zero Defects" concept is valid. | It is shocking that a common topic of debate among quality professionals today is whether the "Zero Defects" concept is valid. |
| |
| ==== What is "Zero Defects" ==== | ==== What is "Zero Defects" ==== |
| This was most popularly demonstrated through Deming’s “[[https://www.youtube.com/watch?v=ckBfbvOXDvU|Red Bead Experiment]]”. In fact, point 10 of [[https://deming.org/explore/fourteen-points/|Deming's 14 points]] specifically rejects the “Zero Defects” concept, stating: <blockquote>//Eliminate slogans, exhortations, and targets for the work force asking for __zero defects__ and new levels of productivity. Such exhortations only create adversarial relationships, as the bulk of the causes of low quality and low productivity belong to the system and thus lie beyond the power of the workforce//. | This was most popularly demonstrated through Deming’s “[[https://www.youtube.com/watch?v=ckBfbvOXDvU|Red Bead Experiment]]”. In fact, point 10 of [[https://deming.org/explore/fourteen-points/|Deming's 14 points]] specifically rejects the “Zero Defects” concept, stating: <blockquote>//Eliminate slogans, exhortations, and targets for the work force asking for __zero defects__ and new levels of productivity. Such exhortations only create adversarial relationships, as the bulk of the causes of low quality and low productivity belong to the system and thus lie beyond the power of the workforce//. |
| </blockquote> | </blockquote> |
| {{ :articles:tree_branches_and_roots_01.svg.med.png?direct&280|Source: http://www.clker.com/clipart-2525.html}} | {{ :articles:tree_branches_and_roots_01.svg.med.png?direct&260|Source: http://www.clker.com/clipart-2525.html}} |
| When performing causal analysis, we must be able to identify and link an “assignable cause” to a problem in order to have a “root cause”. “Assignable Causes” can often be eliminated (e.g., through corrective action). However, when unable to identify and clearly link an “assignable cause” to a problem, we must recognize and acknowledge that those variations are most likely inherent to the process and cannot be eliminated; without completely re-engineering that process. And re-engineering a process may be cost-prohibitive… or impossible (e.g., due to technological constraints/limitations). However, there are usually risk controls we can institute to mitigate the likelihood/probability and/or consequences/impacts of these problems to an acceptable risk tolerance level. | When performing "Cause & Effect" analysis, we must be able to identify and link an “assignable cause” to the event (nonconformity). “Assignable Causes” can potentially be eliminated (e.g., through corrective action). However, when unable to identify and clearly link an “assignable cause” to a problem, we must recognize and acknowledge that those variations are most likely inherent to the process and cannot be eliminated; without completely re-engineering that process. And re-engineering a process may be cost-prohibitive… or impossible (e.g., due to technological constraints/limitations or even "technical contradictions"). However, there are usually risk controls we can institute to mitigate the likelihood/probability and/or consequences/impacts of these problems to an acceptable risk tolerance level. |
| |
| Ultimately, no amount of "cheerleading" or impassioned motivational speeches will ever remove human error. Human error is and always has been "//a normal byproduct of personal effort//" (aka a "common cause" variation with NO assignable cause). Delusional attempts to "eliminate" human error only serve to exacerbate the problem through denial. It is a truly poor reflection on the Quality Profession that such an obviously flawed concept has persisted well into the 21<sup>st</sup> century! | Ultimately, no amount of "cheerleading" or impassioned motivational speeches will ever eliminate human error. Human error is and always has been "//a normal byproduct of personal effort//". However, there are steps that companies __can__ take, such as "error-proofing" (Poka Yoke) or removing the human component from a process through a redesign (aka ReEngineering) of the Process OR taking steps to "//mitigate//" the potential for human errors (e.g., rotating personnel to avoid fatigue). |
| | |
| | Delusional attempts to "eliminate" human error through motivational efforts only serve to exacerbate the problem. It is a truly poor reflection on the Quality Profession that such an obviously flawed concept has persisted well into the 21<sup>st</sup> century! |
| |
| Only through accepting that human error is a "//common cause//" variation can we address the problem for what it truly is. Whenever there is a "common cause" variation in a process, we have two options. We can either change the process OR we can implement risk controls (e.g., to mitigate the risk). For example, changing the process to include "error-proofing" (poke yoke) can eliminate human error by eliminating the possibility of an error being introduced. Alternatively, we can greatly reduce the risk of human error being introduced through: | Only through accepting that human error is a "//common cause//" variation can we address the problem for what it truly is. Whenever there is a "common cause" variation in a process, we have two options. We can either change the process OR we can implement risk controls (e.g., to mitigate the risk). For example, changing the process to include "error-proofing" (poke yoke) can eliminate human error by eliminating the possibility of an error being introduced. Alternatively, we can greatly reduce the risk of human error being introduced through: |
| * Reducing the number of times that people "touch" or move a product (as every instance that a product is touched or moved increases the risk of a defect error being introduced). | * Reducing the number of times that people "touch" or move a product (as every instance that a product is touched or moved increases the risk of a defect error being introduced). |
| |
| | The above list is not intended to be all-inclusive. |
| ==== "How "Zero Defects" followers view "risk" ==== | ==== "How "Zero Defects" followers view "risk" ==== |
| |
