Eliminate Waste: Overprocessing and Defects
Eliminate poor training, non-standard work procedures, and poor communication to eliminate waste
More work and rework than necessary
Getting rid of wasteful work practices may be easier than you think.
Overprocessing is waste caused by applying more processes than are necessary to create a product, service, or component. For example, using overly large or complex equipment makes you guilty of overprocessing.
Defects — flaws in a product or service — are inherently wasteful, because they force a product to be discarded or reworked. So where there are defects, there is likely unnecessary rework, which is a form of overprocessing.
If you have waste, you need to find out what caused it.
One method is 5 Whys, or asking “why” five times whenever a problem occurs. For example, why did this customer file a complaint? Because an error appeared the web site. Why was there an error? Because a programmer inserted inaccurate code. Why didn’t someone check it for accuracy? Because that’s not part of the process. And so on.
Root causes of defects and overprocessing
You’ll soon find that defects and overprocessing have some root causes in common — poor training, non- standard work procedures, and poor communication.
Lack of trust, incorrect equipment or software, misunderstandings, and lack of innovation also contribute to overprocessing.
Defects occur for various reasons — poor processes, variations in a process, or machines that are inaccurately designed or engineered. Insufficient on-the-job training may cause a lack of skills, which can create defects.
Eliminating overprocessing and defects
You can eliminate overprocessing and defects by implementing Lean strategies.
You can make your production processes “mistake proof” using poka yoke measures. These can take the form of equipment sensors or software checks — a system that automatically detects if a component is defective, for example. By enabling employees to trust in the quality of a process, you prevent overprocessing in the form of multiple checks or inspections.
When employees know what to do, they’re less likely to make mistakes. And having fewer mistakes help prevent defects. By providing training, you can ensure employees have a good understanding of processes and equipment capacity.
Statistical process control
Variations cause errors, so minimizing variation helps to reduce defects. To fix variation, you can implement statistical process control, or SPC, which involves analyzing variations within a process. For example, the operations manager at a company that produces sheet metal products applied SPC to detect variation. He found they could significantly reduce defects by installing a laser cutting device.
Like SPC, standard work minimizes variation. It ensures a task is completed the same way each time. If operators always use exactly four turns to tighten a screw, for example, screws are less likely to come loose.
Another initiative you can use to reduce waste is kaizen, or continuous improvement. For example, once supervisors at a grocery store started working as a team, they realized they only needed one manager to sign off on an order.
Lean strategies help support your organization’s efforts to eliminate overprocessing and defect waste.