mqVAL software: For in-house quality control
Find out what affects your measurement process
A special feature of mqVAL is the focus on factors. A factor is anything that might influence the outcome of your measurement results such as:
- the operator,
- the temperature,
- the date,
- or a specific procedure
mqVAL allows you to investigate the effect these factors have on your measurement process, thus enabling you to identify reasons for out-of-control situations.
Try mqVAL free of charge
mqVAL will soon be available as a proprietary software tool. At the moment, QuoData is looking for dedicated pilot testers who will use mqVAL for 12 months free of charge in return for their feedback on the product. Apply now!
What can mqVAL do for your lab?
- Flexible data management: Play around with factors (operator, date, equipment, temperature, storage conditions, etc…) and visualize their effect on the repeatability and in-house reproducibility standard deviations.
- Includes the robust Q/Hampel algorithm: Avoid problems connected with outlier elimination - especially relevant for fields such as microbiology where test results display considerable variability.
- Ease of use: All features can be found in 3 tabs (Preparation, Measured values, Assessment).
Internal Quality Control
Shewhart control chart: different operators are highlighted by different colors.
The basic tool for in-house quality control is the control chart. With mqVAL, the center line and the control limits are either computed on the basis of the current data, or are taken over as reference values which you specify. The control chart thus enables you to quickly determine whether your measurement process is under control.
Furthermore, the automatically computed variability parameters can be compared to your CMCs.
External Quality Control
Overview of z scores for all laboratories for one sample-measurand combination.
If you have access to test results from several different laboratories or you are using reference material, external quality control can also be carried out with mqVAL.
Just as in proficiency testing, the evaluation is performed on the basis of z scores. This feature will be of particular interest if there are no available proficiency tests for your matrix/analyte combination. But it is also ideally suited to in-house quality control across laboratories.
What is the advantage of mqVAL compared to other software, such as Minitab and Analyse-It?
In Minitab and Analyze-it, control charts are just one of large number of features. Thus, if a particular statistical approach (e.g. factorial design) is relevant for control charts, it is up to the user to apply the software in the way that is appropriate.
In mqVAL, the focus is explicitly on:
- control charts
- factorial approach
- robust statistics (thanks to which outlier detection is not necessary)
In other words, the very structure of the software reflects our belief that the factorial approach enhances quality control procedures by enabling the user to identify possible reasons for the out-of-control situation on the basis of the QC data themselves.
Does mqVAL cover the requirements of ISO 17025:2005 section 5.9?
In the simplest sense, the answer is yes.
mqVAL has a number of features that meet each requirement of section 5.9. For a detailed explanation, read below.Section 5.9 is titled, “Assuring the quality of test and calibration results.” It contains two subsections.
Sub-section 5.9.1 outlines five points that can be included in a lab’s quality control procedures for monitoring the validity of test and calibrations:
- regular use of certified reference materials and/or internal quality control using secondary reference materials;
- participation in interlaboratory comparison or proficiency-testing programmes;
- replicate tests or calibrations using the same or different methods;
- retesting or recalibration of retained items;
- correlation of results for different characteristics of an item.
With mqVAL, each point can be met in the following ways:
- Reference values can be defined e.g. for the Center line
- mqVAL has all the functions and calculations necessary to perform the evaluation of small interlaboratory studies. For instance, if no proficiency test is offered for a particular measurand/sample, a laboratory or group of laboratories organize an interlaboratory study using mqVAL.
- Different methods or calibrations can be taken into account by means of the factorial approach described above
- Again, retention of items can be taken into account by means of the factorial approach
- Correlations can be investigated by means of the Youden plot
Within sub-section 5.9.2, the 17025 standard is rather vague. In particular, there is no indication of concrete measures to take in order to “correct the problem and prevent incorrect results”. Regardless, mqVAL enables the user to identify reasons for out-of-control situations, and thus helps the laboratory focus corrective and preventive measures.