Introduction
A laboratory needs more than good equipment and skilled personnel to consistently produce reliable work.
It also needs a system that ensures important activities are appropriately planned, performed, documented, monitored and reviewed.
This is the role of quality assurance.
Laboratory quality assurance is broader than quality control. Quality control focuses on operational techniques and activities used to monitor and control processes, while quality assurance involves planned and systematic activities that provide confidence that quality requirements are being fulfilled.
A strong laboratory quality system therefore brings together people, procedures, equipment, documentation, quality control, risk management, audits, corrective action and continuous improvement.
1. What Is Laboratory Quality Assurance?
Laboratory quality assurance is a systematic approach to ensuring that laboratory activities are appropriately designed, implemented, monitored and improved.
It can cover the entire laboratory workflow, from planning and personnel competence to equipment management, testing processes, documentation and reporting.
Laboratory QA may include:
- Personnel competence
- Standard operating procedures
- Equipment management
- Quality control
- Reagent and material management
- Sample management
- Document control
- Record management
- Internal audits
- Nonconformity management
- Corrective action
- Risk management
- Continuous improvement
The exact requirements depend on the type of laboratory, its activities, applicable regulations and the quality standards or accreditation requirements it follows.
2. Why Is Laboratory Quality Assurance Important?
Quality assurance helps a laboratory establish a structured approach to managing quality.
Without an appropriate quality system, a laboratory may have:
- Inconsistent procedures
- Poorly controlled documents
- Inadequate training
- Uncontrolled equipment problems
- Incomplete records
- Repeated errors
- Weak corrective-action processes
- Difficulty demonstrating compliance
QA does not eliminate every possible laboratory error.
Instead, it provides a framework for identifying risks, controlling processes, detecting problems and improving the laboratory’s operations.
3. Quality Assurance vs Quality Control
Quality assurance and quality control are related but are not the same thing.
A simple distinction is:
Quality control asks:
Is this process or result performing within established requirements?
Quality assurance asks:
Do we have a system that consistently supports quality?
QC is therefore part of the broader quality-management framework.
| Aspect | Quality Control | Quality Assurance |
| Main focus | Monitoring and controlling processes | Systematic assurance of quality |
| Scope | Specific operational activities | Broader laboratory system |
| Examples | Control materials, QC monitoring | Audits, document control, competence, corrective action |
| Main question | Is the process performing as expected? | Is the system capable of supporting quality? |
| Relationship | Part of quality management | Broader framework |
A laboratory needs both.
4. Quality Assurance and the Laboratory Quality System
Quality assurance works best when it is part of an organized laboratory quality system.
A quality system establishes how important laboratory activities are planned, performed, documented and reviewed.
Depending on the laboratory, this may include:
- Organizational responsibilities
- Personnel requirements
- Equipment management
- Purchasing and inventory
- Sample management
- Procedures
- Quality control
- Information management
- Documentation
- Records
- Assessment and audits
- Nonconformity management
- Corrective action
- Risk management
- Improvement activities
The system should reflect the laboratory’s actual activities rather than simply becoming a collection of documents.
5. Competent Laboratory Personnel
People are central to laboratory quality.
Personnel should have appropriate education, training, experience and competence for the activities they perform.
Competence development may include:
- Orientation
- Practical training
- Supervised practice
- Competency assessment
- Refresher training
- Continuing professional development
Training should be appropriately documented.
Competence is also different from simply attending a training session.
A person may attend training without demonstrating that they can perform the assigned activity correctly.
Where appropriate, laboratories should therefore assess whether personnel can perform their responsibilities competently.
6. Standard Operating Procedures
Important laboratory activities should be performed using appropriate and controlled procedures.
Standard operating procedures, or SOPs, help establish consistency by describing how activities should be performed.
An effective SOP may identify:
- Purpose
- Scope
- Responsibilities
- Required materials and equipment
- Procedure
- Safety considerations
- Quality-control requirements
- Documentation requirements
- References
- Version and approval information
SOPs should be controlled so personnel can identify the current approved version.
7. Equipment Management
Laboratory equipment is an important part of the quality system.
Equipment should be appropriate for its intended use and managed throughout its useful life.
Depending on the equipment and laboratory requirements, this may involve:
- Selection
- Procurement
- Installation
- Qualification where applicable
- Acceptance checks
- User training
- Maintenance
- Calibration
- Verification
- Performance monitoring
- Fault management
- Repair
- Decommissioning
Equipment management should not end when an instrument is purchased and installed.
The laboratory should consider the complete equipment lifecycle.
8. Quality Control as Part of Quality Assurance
Quality control provides operational information about whether processes are performing as expected.
For example, QC activities may help identify:
- Unexpected variation
- Shifts in performance
- Trends
- Equipment-related problems
- Reagent problems
- Procedural problems
- Personnel-related issues
When QC identifies a problem, the laboratory may need to investigate the cause and determine whether corrective action is necessary.
This demonstrates how QC contributes to the broader QA system.
9. Document Control
Laboratories rely on documents such as:
- SOPs
- Policies
- Forms
- Work instructions
- Manuals
- Quality procedures
- Equipment procedures
- Reference documents
These documents should be appropriately controlled.
Document control may involve:
- Identification
- Approval
- Version control
- Review
- Distribution
- Access
- Withdrawal of obsolete versions
- Retention where required
One important objective is to reduce the possibility that personnel will accidentally use an obsolete or unauthorized procedure.
10. Laboratory Records
Documents explain what should be done.
Records provide evidence of what was actually done.
Laboratory records may include:
- Equipment records
- Training records
- Competency records
- QC records
- Maintenance records
- Calibration records
- Environmental monitoring records
- Incident records
- Audit records
- Corrective-action records
Good records should be sufficiently clear and retrievable to support laboratory operations, investigations and quality review.
11. Internal Audits
Internal audits can help a laboratory determine whether its quality system is being followed and whether established requirements are being met.
An audit may examine areas such as:
- SOP implementation
- Equipment records
- Training records
- QC practices
- Document control
- Maintenance
- Calibration
- Record keeping
- Corrective actions
Audits should be planned and conducted objectively according to the laboratory’s established procedures.
The purpose is not simply to find faults.
Audit findings can provide useful information for improving the laboratory quality system.
12. Managing Nonconformities
A nonconformity occurs when a requirement has not been fulfilled.
Examples could include:
- An expired reagent being used
- An overdue maintenance activity
- An equipment fault not being documented
- An outdated SOP being used
- A required record being incomplete
- A process not being performed according to the approved procedure
Nonconformities should be managed according to the laboratory’s quality procedures.
The laboratory should determine the significance of the problem and take an appropriate response.
13. Correction vs Corrective Action
Correction and corrective action are related but different.
Correction
A correction addresses the immediate problem.
Corrective Action
Corrective action addresses the cause of a nonconformity to help prevent recurrence.
For example, suppose an outdated SOP is found at a workstation.
Correction:
Remove the outdated copy and replace it with the approved current version.
Corrective action:
Investigate why the obsolete document remained available and improve the document-control process if necessary.
The distinction is important because simply fixing the immediate problem may not prevent it from happening again.
14. Root-Cause Investigation
Some problems require investigation beyond the immediate correction.
For example, if an equipment maintenance activity is repeatedly missed, the laboratory may ask:
- Was responsibility clearly assigned?
- Was the maintenance schedule available?
- Were reminders or monitoring systems adequate?
- Was the equipment being used differently from expected?
- Were required spare parts available?
- Was the procedure clear?
- Was there a training issue?
The purpose of root-cause investigation is to understand why the problem occurred and determine whether changes are needed.
The depth of investigation should be appropriate to the significance and risk associated with the problem.
15. Quality Assurance and Risk Management
Laboratories can use risk-based thinking to identify activities where failure could have significant consequences.
Risk assessment may consider:
- What could go wrong?
- How likely is it?
- What could be the consequence?
- What controls are already in place?
- Are additional controls appropriate?
Risk management should be proportional to the laboratory’s activities.
A laboratory handling complex equipment, critical testing processes or sensitive information may require different controls from a small teaching laboratory.
16. Quality Assurance and Equipment Reliability
Equipment problems can affect laboratory operations and potentially affect the validity of work.
A quality system should therefore address equipment reliability.
Useful equipment-management activities may include:
- Preventive maintenance
- Corrective maintenance
- Calibration
- Verification
- Performance checks
- Fault reporting
- Service records
- Equipment history
- User training
A laboratory should also have a clear process for dealing with equipment that is malfunctioning or unsuitable for use.
Where necessary, equipment should be removed or restricted from service until the appropriate corrective measures have been completed.
17. Calibration and Quality Assurance
Calibration can form an important part of equipment management where measurement performance requires it.
However, calibration should not be confused with maintenance.
Maintenance focuses primarily on keeping equipment in an appropriate operational condition.
Calibration establishes the relationship between measurement indications and appropriate reference values under specified conditions.
A laboratory quality system should therefore identify which equipment requires calibration, verification or other performance checks and establish appropriate procedures for managing them.
18. Quality Assurance and Complaints or Feedback
Feedback can provide useful information about laboratory processes.
Depending on the laboratory, feedback may come from:
- Laboratory users
- Clinicians
- Researchers
- Customers
- Students
- Supervisors
- External organizations
Complaints or significant concerns should be managed according to established procedures.
The laboratory can use relevant feedback to identify:
- Recurring problems
- Communication issues
- Process weaknesses
- Training needs
- Opportunities for improvement
19. Continuous Improvement
A laboratory quality system should not remain static.
Laboratories can use information from:
- QC results
- Audits
- Incidents
- Complaints
- Equipment failures
- Nonconformities
- Staff feedback
- Process reviews
- Performance data
to identify opportunities for improvement.
Continuous improvement does not necessarily mean replacing equipment or introducing expensive technology.
Sometimes improvement may involve:
- Simplifying a procedure
- Improving documentation
- Clarifying responsibilities
- Improving training
- Updating an SOP
- Changing a maintenance schedule
- Improving communication
20. Quality Assurance and Laboratory Documentation
Good documentation should allow the laboratory to demonstrate:
- What was done
- Who performed it
- When it was performed
- Which procedure was followed
- What equipment was involved where relevant
- What happened
- What action was taken when something went wrong
Documentation should support laboratory operations rather than becoming paperwork for its own sake.
A quality system is more useful when records are accurate, accessible, appropriately controlled and meaningful.
21. Common Laboratory Quality Assurance Mistakes
Laboratories should avoid treating quality assurance as simply a documentation exercise.
Common mistakes include:
Treating QA as paperwork only
Having many documents does not automatically mean that a laboratory has an effective quality system.
Ignoring staff competence
An SOP cannot compensate for inadequate training or competence.
Allowing uncontrolled documents
Obsolete procedures can create inconsistency and increase the risk of errors.
Failing to investigate recurring problems
Repeated problems may indicate an unresolved underlying cause.
Performing audits without following up findings
An audit has limited value if significant findings are identified but not appropriately addressed.
Treating corrective action as immediate repair
Fixing the immediate problem may not address the reason the problem occurred.
Ignoring equipment history
Recurring equipment problems may become difficult to identify when maintenance, calibration and fault records are incomplete.
22. Building a Laboratory Quality Culture
A quality system becomes stronger when quality is treated as everyone’s responsibility.
Different people may have different responsibilities.
Laboratory managers establish systems and provide resources.
Supervisors provide direction and monitor activities.
Laboratory professionals follow procedures, perform assigned work and report problems.
Technical personnel may maintain and service equipment according to their responsibilities and authorization.
Quality personnel may monitor systems, coordinate assessments and support improvement activities.
The exact responsibilities depend on the laboratory’s organizational structure.
The important principle is that quality should be integrated into everyday laboratory work rather than assigned only to one person or department.
23. A Practical Laboratory Quality Assurance Cycle
A simple way to visualize laboratory QA is:
Plan → Implement → Monitor → Assess → Correct → Improve → Review
Plan
Establish requirements, responsibilities, procedures and controls.
Implement
Perform laboratory activities according to approved procedures.
Monitor
Use QC, records, observations and other information to monitor performance.
Assess
Use audits, reviews and investigations to identify weaknesses.
Correct
Address identified problems and determine whether corrective action is needed.
Improve
Make appropriate changes to prevent recurrence and improve performance.
Review
Evaluate whether the changes are effective and whether further improvement is required.
This cycle helps demonstrate that quality assurance is an ongoing process.
24. Practical Example: Managing an Outdated SOP
Imagine that a laboratory staff member discovers that an outdated equipment SOP is still available at a workstation.
A possible QA response could be:
Step 1: Immediate correction
Remove the outdated SOP and provide the approved current version.
Step 2: Assess the situation
Determine whether the outdated procedure was actually used and whether the situation could have affected laboratory activities.
Step 3: Investigate
Determine why the obsolete document remained available.
Step 4: Corrective action
Improve the document-control process if the investigation identifies a systemic weakness.
Step 5: Verify effectiveness
Check whether obsolete copies have been removed and whether the revised control process is working.
Step 6: Document
Record the event and actions according to the laboratory’s procedures.
This example shows how QA connects document control, risk assessment, corrective action and continuous improvement.
25. How to Build a Practical Laboratory Quality Assurance System
A laboratory beginning or strengthening its QA system can consider the following sequence:
- Identify applicable requirements.
- Define quality responsibilities.
- Identify important laboratory processes.
- Develop and control procedures.
- Establish personnel competence requirements.
- Establish equipment-management processes.
- Establish QC activities.
- Control documents and records.
- Establish nonconformity and corrective-action processes.
- Conduct appropriate internal assessments or audits.
- Review performance information.
- Implement improvement activities.
- Monitor whether improvements are effective.
- Review the quality system periodically.
The system should be appropriate to the laboratory’s size, activities, risks and applicable requirements.
26. Frequently Asked Questions
What is laboratory quality assurance?
Laboratory quality assurance is a systematic approach to ensuring that laboratory activities and processes are appropriately planned, implemented, monitored and improved to support quality requirements.
What is the difference between QA and QC in a laboratory?
QC focuses on operational monitoring and control of processes, while QA is broader and addresses the system of planned and systematic activities that supports quality.
Is quality control part of quality assurance?
Yes. Quality control is an important component of the broader laboratory quality-management system.
Why are SOPs important for quality assurance?
SOPs help establish consistent methods for performing laboratory activities and provide documented instructions for personnel.
Why is staff competence important in laboratory QA?
Laboratory processes depend on people who are appropriately trained and competent to perform their assigned responsibilities.
Does calibration guarantee that equipment will always produce correct results?
No. Calibration provides information about the relationship between an instrument’s indications and appropriate reference values under specified conditions. Other factors, including sample handling, method performance, equipment condition and operating conditions, can also affect results.
What is corrective action?
Corrective action addresses the cause of a nonconformity to help prevent recurrence. It is different from simply correcting the immediate problem.
What is the purpose of an internal audit?
An internal audit can help determine whether established requirements and laboratory procedures are being followed and identify opportunities for improvement.
Is laboratory QA only for large laboratories?
No. The principles of quality assurance can be applied to laboratories of different sizes and types. The specific quality system should be appropriate to the laboratory’s activities and risks.
How does equipment management support laboratory quality?
Appropriate selection, installation, training, maintenance, calibration or verification, monitoring and fault management can help ensure that equipment remains suitable for its intended use.
Conclusion
Laboratory quality assurance provides a framework for managing quality across the laboratory.
It brings together people, procedures, equipment, documentation, quality control, risk management, audits, nonconformity management, corrective action and continuous improvement.
A strong quality system is not simply a collection of documents.
It is a system that is implemented in everyday laboratory activities and periodically reviewed to determine whether it continues to support the laboratory’s objectives and applicable requirements.
Knowledge Tech Hub Practical Takeaway
A useful way to remember the relationship is:
Quality Control = Monitor and control the process.
Quality Assurance = Build and maintain the system that supports quality.
Quality Management = Coordinate the broader system through which quality is planned, controlled, assured and improved.
The exact terminology and requirements can vary according to the laboratory’s activities and applicable standards, regulations and accreditation requirements.
Suggested Internal Links
- [Laboratory Quality Control: A Practical Guide]
- [Laboratory Equipment Maintenance: A Complete Practical Guide]
- [Preventive Maintenance for Laboratory Equipment]
- [Laboratory Equipment Calibration: What Every Laboratory Professional Should Know]
- [Calibration vs Maintenance: Understanding the Difference]
- [Laboratory Documentation and Record Keeping]
- [Laboratory Standard Operating Procedures (SOPs): A Practical Guide]
- [Common Laboratory Errors and How to Prevent Them]
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References and Further Reading
- World Health Organization — Laboratory Quality Management System resources
- ISO 15189 — Medical laboratories — Requirements for quality and competence, where applicable
- ISO/IEC 17025 — General requirements for the competence of testing and calibration laboratories, where applicable
- ISO 9001 — Quality management systems — Requirements
- International Vocabulary of Metrology (VIM)
- Applicable national laboratory regulations
- Applicable accreditation requirements
- Laboratory quality manuals, SOPs and manufacturer documentation
Note: Laboratories should use the current editions of applicable standards, regulations and accreditation requirements when developing or reviewing their quality systems.
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