Eliminate variation and the need for inspection and rework with Mistake Proofing
Mistake proofing is a way to reduce waste, defects, and variation by designing your business processes so that mistakes or defects cannot occur. Ideally, this means that your process design will not even allow the introduction of a defect. This is the highest level of mistake proofing. Mistake proofing can also prevent defects from occurring or can signal if a defect has occurred, thus preventing the defect from traveling downstream in the process.
Mistake proofing is based on the premise that no matter how hard you work at detecting and reacting to defects, your efforts will not prevent defects from occurring. To prevent defects, you must examine your processes and identify those conditions that lead to the defects occurring. Then you must control those conditions. By reducing defects, mistake proofing can eliminate the need for inspection and can reduce or eliminate waste, variation, and rework.
The use of mistake proofing and the level of mistake proofing are usually determined by the frequency of the mistake occurring or the potential severity of the defect. With issues of safety and security, instances where the defects can be difficult or costly to correct, or frequently occurring issues, preventing a defect from occurring is more desirable than only signaling that a defect has occurred.
Mistake proofing can be:
- Good – The mistake proofing will signal if a defect has occurred or stop the defect from traveling downstream in the process.
- Better – The mistake proofing will prevent a defect from occurring.
- Best – The process design will not allow the introduction of a defect.
Examples of mistake proofing can be found all around you. Consider the following:
- Electronic forms used to collect and validate data
- Almost every plug on a PC designed unique to its purpose
- Elevator doors that reopen when encountering an obstruction
- The “Recycle Bin” in the Windows operating system
- The kill lever on the handle of mechanical equipment
- Spring-loaded castors on rolling staircases that lock in place when someone climbs the stairs
- The ATM that returns your card before dispensing cash
- Color-coded cleaning agents in commercial environments
- Children’s markers that only write on specially treated paper
- The low battery alert on the smoke detector
When improving an existing process or designing a new one, consider ways in which to mistake proof your process or make it “fool proof.” What is the most commonly occurring mistake or what defect of the process is most dangerous or costly? How could the process be mistake-proofed?
Mistake proofing devices are typically simple and inexpensive, but the benefits of the mistake proofing can be invaluable to the organization, process, process owner, and to the end user.
