PROLab: software for interlaboratory comparisons

Z-scores / SDI (Standard Deviation Index)

In order to describe measurement deviations independently of the sample and measured variable (analyte), Z-Scores can be calculated in PROLab. Z-Scores represent the number of standard deviations by which a measurement result is above or below the assigned value.

With PROLab it is also possible to carry out laboratory assessments with flexible tolerance limits and using different scores, e.g. Z'- and Z_u-Scores.

Evaluation across samples and interlaboratory trials

• Z-score histograms with options to evaluate results across samples, labs, tests, or metrics
• Kernel density estimator (KDE)
• Visualization of laboratory performance over time: track the performance of selected laboratories across several interlaboratory tests

Dispersion diagram according to ISO 13528

To assess the laboratories, you can also include the internal laboratory standard deviation in addition to the laboratory mean. For this purpose, the mean values and standard deviations are graphically compared with the associated statistical confidence range.

Kernel density estimator (KDE) according to the Harmonized Protocol (IUPAC, 2006)

The so-called kernel density estimator is used to estimate the result distribution for a selected sample-feature combination. This becomes particularly important if the measured value distribution deviates significantly from the normal distribution. The distribution of results is shown either for all laboratories or for a selected laboratory. The most likely value can also be used to evaluate the laboratories.

HORRAT analysis

The HORRAT trend makes it possible to carry out an interlaboratory study of the dependence of the comparison standard deviation on the respective concentration of the analyte.

For this purpose, the Horwitz ratio, i.e. the quotient of the empirical and the classical Horwitz standard deviation, is shown. You can also choose between the display for one characteristic (with trend correction) and a display for all characteristics.

Analysis of nested interlaboratory tests

PROLab enables the evaluation of nested interlaboratory tests according to DIN ISO 5725-3, in which 2 x 3 measurements are carried out under different conditions (e.g. 3 repeat measurements on 2 different days or by 2 different processors). ) be performed.

The result of this evaluation is the so-called intermediate standard deviation, which provides information about the precision of the procedure in the laboratory if not all conditions are kept constant.

Homogeneity and stability of interlaboratory testing samples

With PROLab you can evaluate tests for the homogeneity of your interlaboratory testing samples. In addition, you can also evaluate stability data with PROLab.

Import the results of your homogeneity test from Excel, code the test portions in PROLab and evaluate the results - including a written interpretation.

PROLab carries out homogeneity and stability analyzes in accordance with ISO 13528 and Harmonized Protocol (IUPAC, 2006).

Inclusive services for PROLab users

• Regular Updates
  PROLab is regularly updated to optimize the use of the program and ensure that it complies with the latest scientific standards and international norms.
• Software validation
  PROLab's quality assurance includes regular validation of calculations as well as automated and manual testing to ensure that reports, calculations and diagrams are output correctly. Software validation is carried out regularly and QuoData can provide its customers with a validation certificate and a full validation report for accreditation purposes.

Additional benefits and services