IATF 16949:2016 Clause Monitoring and measurement of manufacturing processes

Monitoring and measurement of manufacturing processes refer to the systematic and ongoing activities of collecting data and evaluating the performance of various aspects of the production process to ensure its efficiency, effectiveness, and quality. The goal is to continuously assess and control the manufacturing processes to meet the desired product specifications, maintain consistent product quality, and identify opportunities for improvement. The process involves gathering relevant data from various stages and elements of the manufacturing process. This data can include process parameters, operating conditions, material properties, machine settings, and other relevant variables. In many cases, monitoring involves real-time observation of the manufacturing process as it happens. This can be done using sensors, gauges, cameras, or other devices that provide live data on process conditions. Once the data is collected, it is analyzed to identify patterns, trends, and variations. Statistical analysis and process control techniques are often used to gain insights into the process performance. Monitoring and measurement are essential components of quality control. By continuously measuring critical parameters, manufacturers can identify deviations from the desired quality standards and take corrective actions promptly. Monitoring helps assess the stability and capability of the manufacturing processes. Stable processes show consistent performance over time, while capable processes are those that produce products within specified tolerances. Through monitoring and measurement, manufacturers can identify inefficiencies or bottlenecks in the process and optimize it to improve productivity and reduce waste. Monitoring is essential to ensure compliance with industry standards, regulations, and customer requirements. By measuring key parameters, manufacturers can verify that they are meeting the necessary standards. Regular monitoring and measurement provide valuable data for continuous improvement initiatives. By analyzing the data and identifying areas for enhancement, manufacturers can implement changes to optimize their processes. Preventive Maintenance: Monitoring equipment and machines can help detect early signs of potential issues, allowing for timely preventive maintenance to prevent costly breakdowns and downtime. Monitoring and measurement activities also contribute to product traceability, as data records can be used to track and verify the history of products throughout the manufacturing process. In summary, monitoring and measurement of manufacturing processes are crucial for maintaining product quality, process efficiency, and compliance with standards. By continuously collecting and analyzing data, manufacturers can make informed decisions, implement improvements, and ensure that their production processes consistently meet the desired specifications and objectives.

Clause Monitoring and measurement of manufacturing processes

The organization must perform process studies on all new manufacturing (including assembly or sequencing) processes to verify process capability and to provide additional input for process control, including those for special characteristics. The organization must maintain manufacturing process capability or performance results as specified by the customer’s part approval process requirements. The organization shall verify that the process flow diagram, PFMEA, and control plan are implemented, including adherence to measurement techniques; sampling plans; acceptance criteria;records of actual measurement values and/or test results for variable data; reaction plans and escalation process when acceptance criteria are not met.  Significant process events, such as tool change or machine repair, are to be recorded and retained as documented information.The organization must initiate a reaction plan indicated on the control plan and evaluated for impact on compliance to specifications for characteristics that are either not statistically capable or are unstable. These reaction plans to include containment of product and 100 percent inspection, as appropriate. A corrective action plan to be developed and implemented by the organization indicating specific actions, timing, and assigned responsibilities to ensure that the process becomes stable and statistically capable. The plans are to be reviewed with and approved by the customer, when required. The organization must maintain records of effective dates of process changes. For some manufacturing processes, where it may not be possible to demonstrate product compliance through process capability alternate methods such as batch conformance to specification may be used.

You must establish methods and indicators to monitor and measure your manufacturing processes to demonstrate process capability to achieve planned results and identify opportunities to improve the process. Use your organizations cross-functional knowledge of customer requirements, product, technology, manufacturing processes, etc, to determine process monitoring and measuring indicators and controls. Monitoring and measurement may be done manually or by automated means. One way to identify useful measuring and monitoring methods is to review what problems could occur or have occurred within a particular process. Monitor and measure these occurrences and develop process controls (methods) to reduce or eliminate them. Problems (risks) can occur with any of the variables in a process – e.g. – materials, equipment, facility, methods, technology, personnel, computer hardware or software etc. By using fishbone analysis or similar tools, you can develop very useful monitoring and measuring methods and process performance indicators.  Correction refers to action taken to eliminate a detected nonconformity . You must monitor your manufacturing QMS processes, first to determine and establish capability of new processes to conform to requirements and secondly, to monitor these processes over time to verify ongoing stability and capability to meet requirements and thirdly to determine and achieve levels of continual improvement. Use your APQP, FMEA, MSA and PPAP reference manuals for guidance in determining process monitoring and measuring indicators and controls. The output of your manufacturing process design process must specify the manufacturing process capability, reliability, maintainability & availability indicators, as well as process approval acceptance criteria. Your manufacturing process capability performance must conform to the capability documented in your PPAP submission or agreed with your customer in writing. You must keep records of this ongoing conformance to your customer requirements and use this information to identify opportunities to improve the process. The measurement techniques, sampling plans, acceptance criteria and reaction plans must be documented or referenced in your control plan. Managers responsible for corrective action must be promptly informed of product and process nonconformities . Where the customer is significantly affected by a process nonconformity or change, they must be notified. Corrective action plans as well as resulting updated/changed PPAP’s must be reviewed and approved by the customer, when so required. If in doubt, get clarification from the customer.
Use your manufacturing design process and change control process to manage manufacturing process changes. Performance indicators are not needed for this clause as it provides direction for the application of monitoring and measurement performance indicators for all processes. However the output of monitoring and measurement methods used within each process provides useful performance indicators for determining the effective implementation and maintenance of processes. Review the performance indicators within each process covered this far. Performance indicators to measure process effectiveness and efficiency include – productivity; reduction of cycle time, waste, errors, omissions and failures; asset utilization rates (downtime, turnover), etc. Don’t overlook performance indicators to measure compliance with process related regulatory requirements – e.g., reduction in health and safety incident/violation rates; reduction in regulatory reporting violations, etc.

When a new manufacturing process is introduced or significantly modified, it is crucial to conduct process studies. These studies involve the systematic examination and evaluation of the process to understand its characteristics, potential risks, and performance capabilities.Process capability refers to the ability of a manufacturing process to produce products that consistently meet the desired specifications. By performing process studies, the organization can assess whether the new process is capable of meeting the required quality standards. Process control involves managing and regulating the manufacturing process to ensure it operates within defined parameters and produces products of consistent quality. The data and insights obtained from process studies play a significant role in establishing effective process control measures. In the automotive industry and other sectors with critical product requirements, certain product characteristics are designated as “special characteristics.” These are features that have a significant impact on product performance, safety, or regulatory compliance. Process studies help identify and control these special characteristics to prevent defects and ensure product integrity. The information gathered through process studies serves as valuable input for developing control plans, setting process parameters, and implementing control measures. It helps establish a clear understanding of the critical process parameters and how to monitor and control them effectively.Overall, conducting process studies for new manufacturing processes is essential for ensuring that the organization can produce products that consistently meet customer requirements and adhere to industry standards. It supports the establishment of robust process control measures and plays a key role in identifying and managing special characteristics, leading to improved product quality and customer satisfaction.The object of a process control system is to make economic and sound decisions about the actions affecting the process. Data concerning the variations in process performance are collected and analyzed and decisions taken as to whether action on the process is or is not necessary to maintain production of conforming product . However, process control and process capability are not one and the same. A process is in control when the average spread of variation coincides with the nominal specification for a parameter. The range of variation may extend outside the upper and lower limits but the proportion of parts within the limits can be predicted. This situation will remain as long as the process remains in statistical control. A process is in statistical control when the source of inherent variation is from common causes only: i.e. a source of variation that affects all the individual values of the process output and appears random. Common cause variation results in a stable and repeatable distribution of results over time. When the source of variation causes the location, spread, and shape of the distribution to change, the process is not in statistical control. These sources of variation are due to special or assignable causes and must be eliminated before commencing with process capability studies. It is only when the performance of a process is predictable that its capability to meet customer expectations can be assessed. Process capability studies are studies conducted to obtain information about the inherent variation present in processes that are under statistical control, in order to reduce the spread of variation to less than the tolerances specified in the product specification. Preliminary process capability studies are those based on measurements collected from one operating run to establish that the process is in statistical control and hence no special causes are present. Studies of unpredictable processes and the determination of associated capability indices have little value. Preliminary studies should show acceptable results for special characteristics before production approval can be given. These studies and associated indices only apply to the measurement of variables and not to attributes Several measures of process capability have evolved and are presented as indices Cp, Cpk, and Ppk. Acceptable processes are those with a Ppk value greater than 1.67. Those with Ppk between 1.33 and 1.67 may not meet customer requirements but approval may be granted. If the Ppk is less than 1.33, the process is not acceptable. The object of the studies is to compute the indices and then take action to reduce common cause variation by preventive maintenance, mistake-proofing, operator training, revision to procedures and instructions, etc. The inherent limitations of attribute data prevent their use for preliminary statistical studies since specification values are not measured. Attribute data have only two values (conforming/nonconforming, pass/fail, go/no-go, present/absent) but they can be counted, analyzed, and the results plotted to show variation. Measurement can be based on the fraction defective, such as parts per million (PPM). While variables data follows a distribution curve, attribute data varies in steps since you can’t count a fraction. There will either be zero errors or a finite number of errors. Following production launch, process capability and performance should be measured continually in order to demonstrate that your processes remain capable and the capability index continues to rise. Appropriate action should be taken on characteristics that are either unstable or non-capable. Action plans should be implemented to contain process output and continually improve performance.

Customer’s part approval process requirements

The organization must maintain manufacturing process capability or performance results in line with customer requirements, specifically related to the part approval process. Process capability is the ability of a manufacturing process to consistently produce products that meet the desired specifications. It indicates how well the process can control its variation and produce products within the specified tolerances. Maintaining process capability is crucial for ensuring consistent product quality. Performance results is the data and metrics obtained from monitoring and measuring the manufacturing process. This data provides insights into how well the process is performing and whether it meets the required performance standards. The Part Approval Process (PPAP) is a standardized method used in the automotive industry and other sectors to ensure that the manufacturing process is capable of consistently producing parts that meet customer specifications. The customer may have specific requirements for process capability and performance that the organization must adhere to. The organization is responsible for continuously monitoring and measuring the manufacturing process and ensuring that it remains capable and performs as required by the customer’s PPAP requirements. This involves regular data collection, analysis, and process control activities. The organization must communicate the process capability or performance results to the customer as part of the PPAP submission. This ensures that the customer has confidence in the organization’s ability to deliver products that meet their quality expectations. In cases where the process capability or performance does not meet customer requirements, the organization should take corrective actions and implement improvements to bring the process back into compliance. Maintaining manufacturing process capability and performance results as specified by the customer’s PPAP requirements is essential for achieving customer satisfaction, meeting contractual obligations, and demonstrating the organization’s commitment to delivering high-quality products. It involves proactive monitoring, data-driven decision-making, and a continuous improvement mindset to ensure that the manufacturing process remains capable and consistently meets customer expectations.

Verification of process flow diagram, PFMEA and control plan

It is the organization’s responsibility to verify the implementation of essential documents such as the process flow diagram, Process Failure Mode and Effects Analysis (PFMEA), and control plan. This verification process involves ensuring adherence to various aspects related to measurement techniques, sampling plans, acceptance criteria, record-keeping, and reaction plans when acceptance criteria are not met. Let’s break down the key points in the statement:

  1. Process Flow Diagram: The process flow diagram provides a visual representation of the sequence of steps in the manufacturing process. The organization must verify that the process flow diagram accurately reflects the actual process and that all process steps are implemented as specified.
  2. Process Failure Mode and Effects Analysis (PFMEA): PFMEA is a risk assessment tool used to identify potential failure modes, their effects on the product, and the actions needed to prevent or mitigate those failures. The organization must ensure that the PFMEA is appropriately implemented, and the identified risk mitigation measures are put into practice.
  3. Control Plan: The control plan outlines the specific control measures and activities to ensure that the manufacturing process remains in control and capable of meeting quality requirements. The organization must verify that the control plan is followed and that all identified controls are effectively implemented.
  4. Adherence to Measurement Techniques: The organization should verify that the specified measurement techniques for monitoring process parameters and product characteristics are being followed correctly. This may involve using specific instruments, calibration procedures, and data collection methods.
  5. Sampling Plans: Sampling plans determine how samples are taken from a production lot for inspection and testing. The organization must ensure that the correct sampling plans are used and that they align with the relevant standards or customer requirements.
  6. Acceptance Criteria: Acceptance criteria define the quality standards that products must meet to be accepted. The organization must verify that these criteria are clearly defined, communicated, and adhered to during inspection and testing activities.
  7. Records of Measurement Values and Test Results: The organization should maintain records of actual measurement values and test results for variable data. These records provide evidence of product conformity and are essential for traceability and process improvement.
  8. Reaction Plans and Escalation Process: The organization must have documented reaction plans in place to address situations where acceptance criteria are not met. These plans should outline the steps to be taken to investigate the root cause, implement corrective actions, and prevent recurrence. Additionally, there should be an escalation process to notify relevant stakeholders if critical quality issues arise.

Verification of these elements ensures that the manufacturing process is well-controlled, capable, and consistently producing products that meet the required quality standards. It supports the organization’s commitment to quality and customer satisfaction by addressing potential risks, preventing defects, and providing a structured approach for addressing nonconformities.

Reaction Plan

The standard emphasizes the organization’s responsibility to initiate a reaction plan when characteristics of a manufacturing process are either not statistically capable or are unstable. The reaction plan, as indicated on the control plan, should be implemented to evaluate the impact on compliance to specifications. In situations where the process is not capable or stable, the reaction plan may include containment actions and 100 percent inspection, as appropriate. A statistically not capable characteristic is one where the manufacturing process does not have the ability to produce the characteristic within the desired specifications consistently. An unstable characteristic is one where the process exhibits excessive variability over time. The control plan outlines the control measures and activities to ensure that the manufacturing process is in control and capable of meeting quality requirements. Within the control plan, a reaction plan should be specified for addressing situations where characteristics are not statistically capable or are unstable. When the process exhibits characteristics that are not statistically capable or unstable, the organization must initiate the predefined reaction plan promptly. This ensures that appropriate actions are taken to address the issue and prevent nonconforming products from reaching the customer. The reaction plan should include an evaluation of the impact on compliance to product specifications. This involves assessing how the unstable or not capable characteristic affects the final product’s quality and performance. Containment actions are taken to prevent nonconforming products from reaching the customer. This may involve segregating and holding suspect products until the root cause of the issue is identified and corrective actions are implemented. In some cases, 100 percent inspection of products may be necessary to ensure that each item meets the required specifications. This level of inspection is often used when the process is not capable or stable, and the risk of nonconformities is high.The purpose of the reaction plan is to address quality issues proactively and prevent nonconforming products from reaching the customer. By evaluating the impact on compliance to specifications and taking appropriate containment and inspection measures, the organization can mitigate risks associated with unstable or not statistically capable characteristics. The goal is to identify the root causes of the issues and implement corrective actions to improve process capability and stability, thus ensuring consistent product quality and customer satisfaction.

Corrective action plan

It states the requirement for the organization to develop and implement a corrective action plan when the manufacturing process is not stable and statistically capable. The corrective action plan should outline specific actions, timelines, and assigned responsibilities to address the issues and improve process stability and capability. Additionally, the plan may require review and approval by the customer, depending on the circumstances. The organization must first identify that the manufacturing process is not stable or statistically capable. This may be determined through process monitoring, data analysis, or other quality control methods. Once the process instability or lack of capability is identified, the organization must develop a corrective action plan. This plan outlines the steps that will be taken to address the root causes of the issues and improve process performance. The corrective action plan should clearly define specific actions that need to be taken to address the identified problems. These actions may include process adjustments, changes to process parameters, equipment calibration, training, or other measures. The plan should include timelines for implementing each action. Timelines help ensure that the corrective actions are executed promptly and efficiently. The plan should clearly specify who is responsible for each action. Assigning responsibilities ensures accountability and facilitates effective execution of the corrective measures. In some cases, depending on the severity of the issues and customer requirements, the corrective action plan may need to be reviewed and approved by the customer. This ensures that the customer is aware of the actions being taken to address the issues and that the proposed solutions align with their expectations. Implementation: Once the corrective action plan is developed and approved (if required), the organization must implement the identified actions as per the specified timelines and responsibilities. Monitoring and Verification: The effectiveness of the corrective actions should be monitored and verified to ensure that the process becomes stable and statistically capable as intended. This may involve ongoing data analysis and process performance evaluation. By developing and implementing a well-structured corrective action plan, the organization can address process instability and lack of capability effectively. The plan helps in resolving quality issues, improving process performance, and ultimately enhancing product quality and customer satisfaction.

Maintaining records of effective dates of process changes

Maintaining records of significant process events, such as tool changes or machine repairs, is a crucial requirement in quality management to ensure traceability and process control. Additionally, the organization is responsible for keeping records of the effective dates of process changes. These records are vital for quality assurance, process improvement, and compliance with quality management standards .

  1. Significant Process Events: Significant process events refer to any critical activities or changes in the manufacturing process that may impact product quality, process capability, or compliance with standards. Examples include tool changes, machine repairs, equipment adjustments, or process parameter modifications.
  2. Recording of Significant Process Events: When such events occur, the organization must document them in a systematic manner. This documentation should include details such as the event’s nature, date and time, reasons for the event, personnel involved, and any specific actions taken.
  3. Retention of Records: The organization must retain these records for a specified period, as required by relevant quality management standards or customer requirements. Retention periods can vary depending on industry regulations and organizational policies.
  4. Traceability and Root Cause Analysis: By recording significant process events, the organization ensures that there is traceability of actions taken in the event of any issues or non-conformances. These records also facilitate root cause analysis, helping identify the cause of any problems and implementing corrective and preventive actions.
  5. Maintaining Effective Dates of Process Changes: In addition to recording the occurrence of process events, the organization must also keep track of the effective dates of process changes. This information allows the organization to assess the impact of process modifications on product quality and performance over time.
  6. Process Control and Improvement: By maintaining a comprehensive record of significant process events and changes, the organization can effectively manage its processes, monitor trends, and implement continuous improvement initiatives.
  7. Audit and Compliance: Records of significant process events and process changes play a vital role during internal and external audits. They demonstrate the organization’s commitment to process control and compliance with quality standards.

Overall, recording and maintaining records of significant process events and effective dates of process changes are essential practices to ensure transparency, process control, and continuous improvement in the manufacturing environment. These records provide valuable insights for decision-making, risk management, and enhancing the overall efficiency and effectiveness of the organization’s quality management system.

Alternative methods

In certain manufacturing processes, it may not be feasible or practical to demonstrate product compliance through traditional process capability analysis, especially when the process is complex or produces unique products. In such cases, alternative methods can be used to assess and demonstrate product compliance, and one such method is “batch conformance to specification.”Batch conformance to specification involves evaluating product quality by inspecting and testing specific batches of products to ensure they meet the required specifications and quality standards. Instead of relying solely on process capability metrics, this method focuses on verifying the compliance of individual batches of products.Here’s how batch conformance to specification works:

  1. Batch Sampling: In this method, specific batches of products are selected for inspection and testing. The size and frequency of batch sampling depend on the product complexity, the criticality of the characteristics being evaluated, and the level of confidence required.
  2. Inspection and Testing: During the batch sampling, products are inspected and tested against the defined specifications and acceptance criteria. This can involve various quality control techniques, including visual inspections, dimensional measurements, functional testing, and material analysis.
  3. Acceptance Criteria: The acceptance criteria for each batch are typically based on customer requirements, industry standards, or internal quality specifications. Products within the batch must meet these criteria to be considered compliant.
  4. Recording Results: The results of the inspection and testing are recorded, and the compliance of each batch is documented. This data serves as evidence of product quality and can be used for traceability and reporting purposes.
  5. Continuous Improvement: The organization can analyze the data from batch conformance to specification to identify trends, potential issues, or areas for improvement. This information can guide efforts to enhance process performance and product quality.

While batch conformance to specification provides an alternative method for demonstrating product compliance, it is essential to recognize that this approach does not guarantee the stability and capability of the entire manufacturing process. It focuses on assessing the quality of individual batches rather than the overall process performance.Organizations adopting this method should carefully consider its suitability for their specific manufacturing processes and product requirements. In some cases, combining batch conformance to specification with other quality control methods, such as statistical process control and continuous improvement initiatives, can provide a more comprehensive approach to ensuring product compliance and process stability.

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