Think about how important processes are in your everyday life. Many of your actions require a systematic approach, whether you’re doing something as simple as preparing a meal, driving from one place to another or planning your daily work schedule. However, when unexpected events occur, your routine can become disrupted and compromise your ability to complete the task. For example, a last minute appointment can impede on the time you want to spend on another project. Missing ingredients or an unexpected visitor can disrupt meal preparation. A snowstorm can change your driving patterns and prevent you from arriving on time.
In manufacturing, disruptions to standardized process are known as variances. Variability manifests itself in defective products, rework, extra labor hours and lower profits. It can lead to unhappy customers, field failures and lost orders. Variability is usually the byproduct of breakdowns in one of the “6Ms”: man, machines, methods, materials, measurement systems and Mother Nature (the environment). Sound process control procedures can keep the costs of variances to a minimum.
In any manufacturing process, the property of a produced good will fluctuate slightly from its designated value even when the operation is functioning normally. Most processes are able to account for these “normal curve” standard variations. However, if the core production process or its environment changes—for example, machine wear—distributions can change and products can be created that are outside of the tolerances (acceptable standard deviations away from the mean) of the manufacturer or consumer, resulting in significant waste.
In order to make processes run smoothly, the chance for variability must be reduced as much as possible. In a Six Sigma world, acceptable process control means having only 3.4 defects per million opportunities. Six Sigma standards can be achieved when manufacturers follow well-defined processes within specific limits and reduce variability by creating room for unexpected events.
Many large multi-nationals have asked their suppliers to put an emphasis on deploying process control methodologies to reduce the number of defective parts they deliver. Suppliers use root cause analyses to understand why variation is occurring, and then implement corrective actions and continuous improvement strategies to improve quality and delivery. These actions may include:
- Developing project plans with owners and target dates to identify and implement Permanent Corrective Actions (PCAs) to generate sustained improvements
- Utilizing Layered Quality Audits
- Establishing standardized processes
- Utilizing APQP/PPAP process as a key enabler
- Implementing process control monitoring procedures
- Eliminating non-value-added activities and processes, increasing capacity and reducing cost
- Updating FMEA & process control plans
- Deploying 6-Sigma.
Whether you’re pursuing compliance with an international quality standard or not, the goal is the same: to substantially reduce defective parts and maintain business with your key customer. IBI