Measurement Equipment Monitoring in the Laboratory: How to Organize Maintenance and Calibration in Compliance with Standards

Maintenance and calibration planning in the laboratory: Why Excel spreadsheets are no longer sufficient

In many laboratories, maintenance and calibration appointments are still organized using Excel spreadsheets, Outlook reminders, or handwritten notes. As long as only a few devices are in use, this usually works quite well. However, as soon as the laboratory grows, accreditation according to DIN EN ISO/IEC 17025 is pending, or one works in a GMP or GLP laboratory, the weaknesses of these isolated solutions become apparent: appointments are missed, responsibilities remain unclear, documentation is incomplete or scattered, and during an audit, the auditor finds no consistent documentation.

The result is gaps in measuring equipment monitoring, non-traceable calibrations, unplanned downtime, and critical discussions with auditors or authorities. Professional maintenance and calibration planning is therefore not a "nice-to-have," but essential for effective laboratory management. Especially in the context of increasing regulatory requirements and growing digitalization, structured, audit-proof equipment management is needed to demonstrate the functionality and traceability of all relevant testing and measuring equipment at any time.

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What standards and regulations specifically require

Those working in accredited or regulated fields operate within a clearly defined framework. DIN EN ISO/IEC 17025 explicitly requires that all measuring and testing equipment be suitable, regularly monitored, and maintained. Calibrations must be traceable to national or international standards, and the status of each device must be readily apparent. Documentation, status marking, and assessment of measurement uncertainty are central aspects of test equipment calibration monitoring.

Similar requirements are set out in DIN EN ISO 15189 for medical laboratories, which additionally addresses patient-related measurements. Here, traceability, validity of results, and structured monitoring of measuring instruments are particularly critical.

In GMP and GLP laboratories, the requirements are even stricter: Here, stringent rules apply to equipment qualification, status labeling, documentation, and release. Equipment may only be operated in a released state, and all measures must be documented in a traceable and verifiable manner.

A cross-cutting issue is data integrity according to the ALCOA principle. This requires that all entries relating to maintenance, repair, qualification, and calibration must be traceable, legible, recorded promptly, available in their original form, and accurate – supplemented by completeness, consistency, durability, and availability. Therefore, poorly maintained Excel spreadsheets and loose notes in folders are generally no longer sufficient.

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Think risk-based: Not all devices are equally important.

Modern instrument monitoring follows a risk-based approach. First, the criticality of the devices is assessed: Which ones have a direct impact on release decisions, patient outcomes, or regulatory audits? These devices require more frequent monitoring and stricter traceability and documentation requirements.

Maintenance and calibration intervals are determined based on manufacturer specifications, empirical data, failure history, and process relevance. Regular review of these intervals based on deviations and trend analyses is crucial.

Traceability and validity are crucial: Calibrations of critical test equipment must be traceable to national or international standards – this is a core requirement of DIN EN ISO/IEC 17025. The status of the test equipment (released, blocked, out of service) must be identifiable at all times.

After each calibration, a documented assessment is carried out to determine whether the test equipment remains suitable for its intended purpose. Decisions and assessments must be documented in a traceable manner as part of the test equipment management system.

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How to proceed systematically

The development of a structured system follows a clear plan. First, all relevant testing and measuring equipment is inventoried with unique identification (ID, location, responsible person) and assigned to processes, methods, and products.

The next step is the classification of criticality by categorizing it into classes (high, medium, low) according to its impact on outcome quality and patient safety. For each class, measures and intervals are defined: scope of maintenance, scope of calibration, qualification requirements, and documentation requirements.

Documentation should be standardized – through uniform forms or digital forms for maintenance reports, calibration protocols, and qualification documents. While the ALCOA principle is explicitly required, especially in GMP and GLP laboratories, data integrity requirements are also continuously increasing in ISO-accredited laboratories. The advantage of modern software is that it often implements these principles – assignable entries, timestamps, electronic signatures – seamlessly, without complicating matters for users. Data integrity doesn't have to mean bureaucracy. Those who invest in a well-designed system today are also well-prepared for future requirements – regardless of whether they operate according to DIN EN ISO/IEC 17025, DIN EN ISO 15189, or in a regulated sector.

The crucial step is the introduction of a central system: replacing distributed Excel files with a structured solution for lab equipment management. As part of digitalization, the use of a central platform that links maintenance, calibration, and qualification data with SOPs, logbooks, and quality documents is highly recommended.

Finally, training and role clarification with defined responsibilities for test equipment management, maintenance coordination and release, as well as regular training for laboratory managers, QA/QM and technical staff are needed.

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Planning with a holistic view: deadlines and resources

Good planning takes into account not only deadlines but also resources. Annual planning consolidates all maintenance, calibration, and qualification dates in a central calendar, taking into account peak periods, vacation times, and ongoing projects.

Resource leveling ensures that sufficient alternative equipment or capacity is available during maintenance. Redundancies or contingency plans should be defined for critical equipment.

Status management ensures clear identification of devices (e.g., "under maintenance," "calibrated until...", "locked out"). Integration with laboratory management software allows all employees to view the status at any time. This minimizes downtime and avoids bottlenecks in routine operations.

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Digitalization as a sustainable path

As digitalization progresses, more and more laboratories are relying on specialized test equipment management software. These systems support the centralized management of all test and measuring equipment, automatic reminders for maintenance and calibration appointments, the storage of certificates, service reports and qualification documents, as well as status labeling and audit trail functionalities.

For smaller laboratories, simple or even free software solutions for monitoring test equipment can be a good starting point. They replace, at the very least, the fragmented test equipment monitoring system using Excel and create initial structure in equipment management.

For regulated environments with GMP or GLP laboratories, a professional system is usually necessary that offers ALCOA-compliant logging, user and rights management concepts, and interfaces to other systems. Modern laboratory management software combines test equipment monitoring, measuring instrument management, and equipment history with SOPs, logbooks, and quality documents, thus supporting integrated equipment management.

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What has proven effective in practice

Several tried-and-tested principles have become established. “Single Source of Truth” means that all information relating to test equipment monitoring, maintenance, qualification, and calibration is maintained in one place.

Roles and responsibilities should be clearly defined: Laboratory managers, quality assurance/quality management, and technical staff should have clearly assigned tasks and authorities. Standardized workflows ensure consistent procedures for maintenance, calibration, qualification, verification, and release decisions.

The integration with quality management ensures that deviations from calibrations (such as the unsuitability of a device) are automatically incorporated into CAPA or deviation processes. Regular reviews—an annual review of intervals, service providers, costs, and downtime—enable continuous improvement.

The result is a consistent system that meets the requirements of DIN EN ISO/IEC 17025, DIN EN ISO 15189, as well as specifications for GMP laboratory and GLP equipment.

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Why the effort is worthwhile

Efficient maintenance and calibration planning is a key element of professional laboratory management. It protects against downtime, reduces the risk of inaccurate measurements, and provides security for auditors and regulatory authorities.

Those who consistently move away from isolated solutions such as Excel-based test equipment monitoring and rely on structured, digital lab equipment management not only meet the requirements of ISO 17025, ISO 15189, GMP and GLP, but also increase efficiency and transparency in everyday laboratory work.

A well-designed test equipment management system with clearly defined processes, risk-based planning, digital test equipment monitoring, and traceable documentation is therefore not an additional expense, but rather the foundation for a robust, future-proof, and audit-proof laboratory. Whether an internally developed solution or a specialized platform is used is secondary – what matters is that maintenance, calibration, and test equipment management are consistently, traceably, and audit-proofly organized.