| Error Proofing is a process improvement that aims to | | | | seeks to determine the root cause by repeatedly |
| prevent a specific defect from occurring in a | | | | drilling down through asking the question why. |
| production line. Effective error proofing involves | | | | With knowledge of the cause of the error, the team |
| detection of the error by the operator, feedback to | | | | can them conduct a solution finding exercise in order |
| stop the process, so that the error can be put right | | | | to develop an effective manual or automated, |
| and problem solving by the improvement team to take | | | | integrated error proofing system. Such a system might |
| corrective and preventative action. | | | | include limit or touch switches, photo-electric sensors or |
| Error proofing reduces the risk of:o Operator injuryo | | | | proximity switches. In all cases the triggering of the |
| Faulty productso Machine damage ando Defective | | | | error proofing system will set off an alarm and/or halt |
| product being produced or passed to the next process | | | | the production process so that the error can be |
| The change agent's challenge is to change the culture | | | | rectified. |
| within an organization so that the new mantra | | | | Low cost error proofing devices which are |
| becomes: | | | | inexpensive to replace make good economic sense. |
| Don't accept a defect | | | | The ideal situation is to design a product that cannot |
| Don't make a defect and | | | | be assembled incorrectly, so at best, devices should |
| Don't pass a defect on (to the customer) | | | | prevent the ability to make a defect. However, if the |
| Lean Six Sigma is a currently popular change | | | | defect cannot be prevented, the device should |
| management methodology in which the term for error | | | | prevent it from being passed to the next production |
| proofing is Poka Yoke. The number one objective of | | | | process. |
| poka yoke is to achieve zero defects. | | | | It is also imperative that the device provides prompt |
| Error proofing enforces procedures which are set in | | | | identification of defect location, allowing for quick |
| stone ensuring quality and almost entirely eliminating | | | | troubleshooting. Error proofing deployment needs to be |
| defects. As such, it:o Eliminates the cost of product | | | | a rapid process since minimal disruption of the system |
| inspections since none will be necessaryo Makes | | | | means limited loss of income to the organization. Initial |
| waste costs insignificanto Frees up operator time for | | | | investigations to device implementations should |
| the task at hand rather than problem solving ando | | | | certainly span, no more than a month for minimal |
| Promotes an attitude of continuous improvement. | | | | process disruption. |
| A defect is a product that fails to meet set | | | | Dividing the error proofing procedure into small steps |
| specifications whereas an error is any deviation from | | | | each assigned to a named operator has proven a |
| set process. In the error proofing process, inspection of | | | | particularly effective approach when it comes to |
| the product occurs after each process is complete, so | | | | getting quick results. It has also been proven beneficial |
| that errors can be detected close to their causative | | | | to run daily review sessions and to address issues |
| source. Once the causative process has been | | | | raised promptly. |
| identified, the team then brainstorms all possible errors | | | | Assessment of the impact of changes made needs to |
| that might have resulted in the relevant defect. | | | | be frequent. Further, as the system becomes more |
| Quantitative data is recorded and special note of | | | | active in error detection, it will become possible to |
| potential causes that occur on an ongoing basis is | | | | detect errors at an earlier stage so that new error |
| noted. Finally, the root cause is identified by testing out, | | | | proofing solutions should continue to be sought on an |
| often by a questioning technique called 5-Why which | | | | ongoing basis. |