Quality audits are performed to verify the effectiveness of a quality management system. They can also be used to:
- Gain internationally recognized quality certifications, such as ISO 9001.
- Verify the existence of objective process data.
- Assess how successfully processes have been implemented.
- Judge the effectiveness of achieving any defined target levels.
- Provide evidence concerning reduction and elimination of problem areas.
- Ensure the achievement of continual improvement in an organization.
To perform a quality audit effectively, practitioners can use Six Sigma’s DMAIC roadmap as an organizational resource. Six Sigma provides the tools to improve the capability and reduce the defects in any process, and quality audits can benefit from this structured approach.
The basic Six Sigma roadmap used to improve existing processes consists of the following steps:
- Define high-level project goals and the current process.
- Measure key aspects of the current process and collect relevant data.
- Analyze the data to verify cause-and-effect relationships. Determine what the relationships are, and attempt to ensure that all factors have been considered.
- Improve or optimize the process based on data analysis using techniques such as design of experiments.
- Control the process to ensure that any deviations from target are corrected before they result in defects. Set up pilot runs to establish process capability, build in control mechanisms and continuously monitor the process.
The purpose of quality audits is to verify the existing system for compliance to established standards; therefore, DMAIC can be used to manage audit activities.
Audit Cycle Using DMAIC
A quality audit can be completed in five steps:
1. Plan Audit and Define Audit Agenda
Practitioners can set the audit agenda by answering the five Ws and one H: Who, When, Where, What, Why and How. The agenda should include the goal of the audit, the name of the person conducting the audit, the date it will be conducted, the venue, what is to be audited and the reason why the audit is to be conducted. The auditor should also be clear about the directions to be followed during the audit. To cover every critical aspect, a checklist could be used.
2. Conduct Audit and Measure Performance
The audit should be conducted according to the scope and goal defined in the audit agenda. The auditor will measure key aspects of the current process and collect relevant data. Of course, every organization must follow its defined policy and the regulatory norms of its country. Audits should also be conducted to review processes and systems of an organization; by measuring their performance, practitioners can determine their reliability.
3. Record Results and Analyze Findings
All problems found during audits should be documented and categorized in order of their importance. Problems can be categorized as critical, major or minor, based on the significance of their break with organizational policy.
Audit reports provide a balanced overview of the current process, with details about any under- or over-performing metrics. All problems observed during the audit should be sent to the organization’s leadership, with critical and major noncompliance issues flagged as early as possible.
4. Uncover Trends and Make Improvements
Auditors should highlight process areas that show excellence and best practices. They should also separate all critical and major problems from the minor problems so the organization can focus improvement efforts accordingly.
Problem importance can be determined after conducting a root cause analysis of the process issues. Causes can be mapped on a Pareto chart, which typically reveals that 20 percent of the problems create 80 percent of the negative impact on a quality system. Through the use of the Pareto chart, practitioners can identify areas of improvement and suggest necessary changes.
5. Control System with Follow-up Audit
After defining process control limits, auditors can identify and implement measures, such as control charts, to help prevent problems from occurring again. Follow-up audits are required to measure actions taken to improve processes and systems of organization.