Equipment Qualification for Laboratory Balances and Analytical Equipment
Note: This section "Equipment Qualification" is based mainly on the book "Validation and Qualification in Analytical Laboratories" written by Ludwig Huber (ISBN:1-57491-080-9).
Equipment Qualification (EQ) is used as an "umbrella-term" to cover the four steps that ensure a balance or instrument is appropriate for its intended use. The user has the ultimate responsibility for the accuracy of results and for the qualification of his/her equipment. METTLER TOLEDO breaks EQ down into:
Design Qualification (DQ) defines the fuctional and operational specifications of a balance or instrument.
Installation Qualification (IQ) ensures that a balance or instrument is received as designed and specified. It documents the installation in the selected user environment.
Operational Qualification(OQ) demonstrates that a balance or instrument will function according to its operational specification in the selected environment.
Performance Qualification (PQ) demonstrates that a balance or instrument consistently performs according to a specifiction appropriate for its routine use.
Design qualification (DQ) defines the functional and operational specifications of the instrument and details the conscious decisions in the selection of the supplier. DQ should ensure that instruments have all the necessary functions and performance criteria that will enable them to be successfully implemented for the intended application and to meet business requirements. Errors in DQ can have a tremendous technical and business impact, and therefore a sufficient amount of time and resources should be invested in the DQ phase. For example, selecting a vendor with insufficient support capability can decrease instrument up-time with a negative business impact. METTLER TOLEDO provides a pdf-file to support customers during the specification phase.
The list below shows the recommended steps that should be considered for inclusion in a design qualification.
The Balance Log Book provided by METTLER TOLEDO contains a DQ section to support definition of functional and operational specifications.
Click to see a Design Qualification example for a METTLER TOLEDO titrator.
As part of the design qualification process, the vendor should be qualified; the question is how should this be done? Is an established and documented quality system enough, (e.g. ISO 9001) or should there be a direct audit?
The answer is that there may be situations where a vendor audit is recommended: for example, when complex computer systems are being developed for a specific user. However, this is rarely the case for balances and analytical instruments.
If equipment does not include a computer system a good reputation, own experiences or good references from other users together with ISO9001 certification, can be sufficient.
When the equipment to be purchased is an off-the-shelf commercial system such as a titrator or thermal analysis system that includes a computer for instrument control and data handling, it is recommended following these steps:
Develop a vendor qualification checklist. This list should include questions on how the equipment is developed, validated, installed and supported. The points to consider are:
- For products that include software, does the vendor comply with ISO 9000-3 (Guidelines for the application of ISO 9001 to the development, supply and maintenance of software) or an equivalent standard?
- Is equipment hardware and computer software developed and validated according to a documented procedure (according to a product life cycle)?
- Is the vendor prepared to make product development and validation records and source code accessible to regulatory agencies?
- Does the vendor provide declaration of conformity to documented specifications?
- Does the vendor provide assistance in design qualification, equipment installation, qualification, maintenance and timely repair through qualified employees?
Send the checklist to the vendor. If the vendor answers all the questions satisfactorily within a given time frame, the vendor is qualified.
If the vendor does not answer the questions satisfactorily, another vendor should be considered. If there is no other vendor who could provide an instrument that meets the operational and functional specifications, a direct audit should be considered.
Installation qualification establishes that the instrument is received as designed and specified, that it is properly installed in the selected environment, and that this environment is suitable for the operation and use of the instrument. The two tables below list steps as recommended before and during installation.
- Obtain manufacturer's recommendations for installation site requirements.
- Check the site for the fulfillment of the manufacturer's recommendations (utilities such as electricity, water and gases and environmental conditions such as humidity, temperature, vibration level and dust).
- Allow sufficient shelf space for the equipment itself, related SOP's, operating manuals, log books and software.
- Compare equipment, as received, with purchase order (including software, accessories, spare parts).
- Check documentation for completeness (operating manuals, maintenance instructions, standard operating procedures for testing, safety and validation certificates).
- Check equipment for any damage.
- Install hardware (equipment, computer, printers, modules).
- Switch on the balance or instrument(s) and ensure that equipment powers up.
- If applicable install software on computer following the manufacturer's recommendation.
- Verify correct software installation, (are all files loaded). Utilities to do this should be included in the software itself.
- Make a back-up copy of software.
- Configure peripherals (printers and equipment modules).
- Identify hardware and complete list in log book, include drawings where appropriate.
- If applicable identify and record all software installed on the computer.
- List equipment manuals and SOP's.
- Complete installation report.
- In-house identification number (asset number)
- Name of the item or equipment
- Manufacturer's name, address and phone number for service calls, service contract number
- Serial number of equipment
- Computer hardware with information on processor, hard disk space
- Installed software and revision number
- Date received
- Date placed in service
- Current location
- Condition when received, for example, new, used, reconditioned
- List with authorized users and responsible person
Functional and operational testing belong to OQ. IQ does only include tests to verify that the software and hardware are installed properly and that all electrical and fluid connections are correct. Therefore IQ should include switching on the instrument and checking for any error messages.
Operational qualification(OQ) is the process of demonstrating that an instrument will function according to its operational specification in the selected environment. Frequent questions regarding OQ are:
What should the acceptance criteria be? Should they be in line with the manufacturer's specifications, or should they reflect the intended use of the equipment?
Should I use the same procedures and acceptance criteria for all instruments of the same type in my laboratory and/or in our company?
How frequently should OQ tests be done?
Should the test be done by the vendor or by the user?
Should I do preventive maintenance before theOQ test?
Should I requalify the equipment after moving the instrument to another lab?
Should I requalify the equipment after repair or after firmware, software and hardware upgrades?
Why do I need OQ at all if I use the equipment for one specific application only, isn't performance qualification enough?
If a balance or instrument is to be used for one application only, tests and acceptance criteria should be limited to that application. In this case, the test compound can be the same as the compounds analyzed in unknown samples.
The frequency of OQ depends on the type of instrument, on the stability of the performance parameters, butalso on the specified acceptance criteria. In general, the time intervals should be selected such that the probability is high that all parameters are still within the operational specifications. Otherwise, analytical results obtained with that particular instrument are questionable.
Performance Qualification (PQ) is the process of demonstrating that an instrument consistently performs according to a specification appropriate for its routine use.
Important here is the word consistently. The test frequency is much higher than for OQ. Another difference is that PQ should always be performed under conditions that are similar to routine sample analysis.
PQ should be performed on a daily or at least a weekly basis or whenever the instrument is used. The test frequency not only depends on the stability of the equipment but on everything in the system that may contribute to theanalysis results. In practice, PQ can mean system suitability testing where critical key system performance characteristics are measured and compared with documented preset limits. The table below gives a recommendation for a PQ example for a balance.
2. Select critical parameters. For a balance this can be:
- Testing of one to several points
- Defining test points
- Defining Weights and Weight Classes to be used
- Decision if certified and traceable weights have to be used for testing
- Defining acceptance limits of results
3. Define the test intervals:
- weekly, e.g. every Monday morning
- every day
- every time the balance is used
- before, between and after a series of runs
4.Define corrective actions on what to do if the balance does not meet the criteria, in other words if the results are out of specification. METTLER TOLEDO provides a SOP for a performance test in the Balance Log Book.
Balances and analytical instruments are usually purchased from a vendor, so a frequently asked question is whether the vendor or the user should perform equipment qualification. Here it should be noted that the user has the ultimate responsibility for the accuracy of the analysis results and therefore also for equipment qualification. What the user does in this respect depends again on the type of equipment, and especially on its intended use.
DQ should always be done by the user. The instrument's functional and performance specifications from the vendor can be used as a source of information, but they always should be adapted to the specific, intended use of the system.
While IQ for a small and low cost instrument, such as a pH meter, may be done by the user, IQ for balances, titrators or Thermo Analysis systems should be done by the vendor.
PQ should always be done by the user because it very often depends upon a specific application. As PQ is done much more frequently than OQ, this practically limits this task to the user anyway.
On completion of equipment qualification, documentation should be available that consists of:
- Design and vendor qualification document
- Installation qualification document (IQ Protocol)
- List of authorized users
- List of authorized service technicians
- Calibration certificate that documents initial calibration
- Log that lists all activities involving the equipment
- PQ test procedures and representative results
- Entries on instrument ID in the laboratory's instrument data base