Implementing a statistical process control (SPC) system for improved quality control

Introduction to Statistical Process Control (SPC)

Statistical Process Control (SPC) is defined as the use of statistical techniques for measuring and controlling quality by monitoring the process. It involves using statistical methods to measure and analyze the variations in a process to ensure it operates consistently and produces products or services within specified quality standards.

Why use Statistical Process Control (SPC)?

Prevention-based control: In the era of increasing competition, with an increase in the cost of raw materials, Companies must strive for increased improvement in quality and cost reduction. The majority of the companies still rely only on inspection after production to detect quality issues. An organization can move from detection-based quality controls to prevention-based quality controls by implementing the SPC procedure. An operator can identify patterns or modifications in a process before they lead to non-conforming goods and scrap by keeping an eye on the process’s performance in real time.

Reduced cost: SPC techniques and tools can assist you in tracking process behavior, identifying problems in internal systems early on, and solving production problems by balancing efficiency and cost reduction with quality improvement.

Improvement in Process: By monitoring and analyzing data over some time, SPC identifies trends and patterns that help for improvement in business processes.

Informed decision-making: SPC provides objective data and insights about the process performance, enabling informed decision-making based on evidence rather than assumptions. It helps identify deviations early, allowing prompt action before they escalate into larger problems.

How to Use Statistical Process Control (SPC)?

Clear Objectives and Goals: Clearly define the process you want to monitor. It could be product quality, reducing defects, or enhancing process efficiency, etc.

Stability: Ensure the process is stable and predictable before implementing SPC. Unstable processes may yield misleading results on control charts.

Determining the lag: Before implementing SPC, the manufacturing process should be evaluated to determine the areas of waste. It is very crucial to implement SPC tools in the main areas of waste first. Some instances of manufacturing process waste are over-processing defects and additional inspection time.

Employee Training and Involvement: Involvement of employees is very important for the implementation of SPC. Giving them proper training and making them understand the principles of SPC, how to collect data, interpret charts, and take corrective actions nurtures ownership and a culture of continuous improvement.

Data Collection: Identify the variables or attributes critical to the process’s quality and establish a system for collecting accurate and reliable data. Collect data regularly and consistently.

Statistical Tools and techniques: SPC tools help track process behavior, identify problems with internal systems, and resolve production-related issues. Establish appropriate statistical tools and techniques for analyzing the data. The employment of tools like check sheets, control charts, histograms, or Pareto charts helps in making data-driven decisions. A Popular SPC tool is an SPC control chart which helps one record data and lets you see when an unusual event, such as a very high or low observation compared with “typical” process performance, occurs.

Establishing Control Limits: Determine control limits for process parameters based on statistical analysis. These limits signify the range within which the process should operate to ensure it’s in control. Out-of-control points trigger investigations and corrective actions.

Continuous Monitoring and Analysis: Regularly monitor process data and analyze it using SPC tools. This continuous assessment helps identify trends, variations, and any deviations from established control limits, allowing for timely corrective actions.

Review and Adaptation: Periodically review the SPC implementation to assess its effectiveness in meeting objectives. Adapt the SPC process based on feedback, changes in the environment, or new insights gained.

Implementing SPC: Real-world Applications

Strategic process control could be used in Manufacturing industries, service industries, and healthcare or Pharmaceutical Sectors.

Manufacturing Industries:

• Car manufacturing companies use SPC to monitor their production lines by reducing scrap and, ensuring consistency in engine performance, bodywork quality, and assembly precision.
• SPC helps pharmaceutical companies maintain strict quality control in drug manufacturing. It also ensures that it operates at full potential to produce conforming output. Control charts monitor variables like temperature, pressure, and ingredient proportions to ensure precise and consistent medication production.

Healthcare:

• SPC is applied to improve patient care by monitoring waiting times, medication administration accuracy, and infection rates. It ensures processes adhere to established standards, enhancing overall healthcare quality.
• In producing medical equipment, SPC guarantees adherence to safety and quality standards. Control charts track parameters such as device dimensions, materials, and performance metrics to meet regulatory requirements.

Service Sector:

• SPC tools assist in monitoring call times, customer satisfaction rates, and issue resolution. Control charts help identify trends, enabling call centers to improve response times and service quality.
• SPC is used to track and analyze transaction times, error rates, and fraud detection accuracy. Control charts aid in identifying anomalies and streamlining processes to enhance security and efficiency.

Sustaining SPC for Continuous Improvement

Continuous Improvement Culture:

• Adopt Kaizen philosophy, emphasizing small, incremental improvements. Encourage a culture where even minor process enhancements are valued.
• Establish feedback mechanisms to collect suggestions and insights from employees regarding SPC effectiveness and areas for improvement.

Performance Monitoring:

• Establish and monitor KPIs related to SPC implementation. Track improvements and successes resulting from SPC initiatives.
• Conduct periodic reviews and audits to assess the effectiveness of SPC processes and identify areas needing improvement.

Knowledge Sharing and Documentation:

• Document successful SPC practices and case studies within the organization for knowledge sharing and future reference.
• Implement mentorship programs where experienced SPC practitioners can guide and mentor others within the organization.

Celebrating Success and Recognition:

• Acknowledge and celebrate individuals or teams that contribute significantly to SPC-driven improvements. Highlight their successes to motivate others.
• Regularly communicate success stories and the positive impact of SPC on the organization to reinforce its value.

Long-Term Planning and Adaptation:

• Align SPC efforts with long-term strategic objectives. Continuously adapt SPC methodologies to meet evolving business needs and market changes.
• Encourage innovation in SPC methodologies. Be open to adopting new tools or approaches that can further enhance SPC effectiveness.

Motorola’s Case Study and Success Story:

Case Study: Motorola, a high-tech company offering highly reliable products, is renowned for its Six Sigma methodology, which incorporates SPC principles in the 1980’s.

Success Story: Motorola utilized SPC to improve the quality of its products. After implementing SPC tools like control charts, they successfully reduced defects and improved their production processes. They documented more than $16 billion in savings. This initiative led to significant cost savings and increased competitiveness in the market. Since then, more than ten thousand companies have started following the Six Sigma methodology to enhance their production process.

Conclusion: The Power of Statistical Process Control

In conclusion, the implementation of a Statistical Process Control (SPC) system stands as a cornerstone for achieving and sustaining superior quality control standards. Its data-driven approach empowers organizations to detect variations, identify trends, and proactively address potential issues before they escalate. By harnessing the power of statistical analysis, businesses can not only enhance product quality but also streamline operations, reduce waste, and bolster customer satisfaction. Embracing SPC signifies a commitment to continuous improvement, enabling companies to adapt, innovate, and thrive in today’s dynamic and competitive markets.