Six Sigma "DOWNTIME" and Analysis or Bioanalysis
Ed O'Connor
Open for contract remote work 1) GxP QA auditor. 2) GxP method Development. 3) GxP Method, Process, Software, Instrument and Computer System Validation. 4) Data Integrity. 5) Statistics- Minitab (ROC, etc.)
DOWNTIME with applications to Analytical and Bioanalytical.
One of the eight deadly wastes considerations in the Six Sigma concept of wastes captured in the acronymous title “DOWNTIME” is Excess Processing, the “E” in DOWNTIME. Consider the application and use of more than 100 acceptance criteria in a quantitative assay. Anyone should recognize this number as extra processing and a “deadly waste.”
In a quantitative assay the criteria are linearity of the curve, accuracy of the response for QC and curve points (knowns), precision of the curve points, QCs and performance of the blanks, LLOQ and ULOQ (knowns) and samples (unknowns), the latter if there are replicates of the samples (unknowns).
If the Curve points and linearity and QCs samples fail to meet the acceptance criteria, the assay fails and there are no values for unknowns. If the curve and QCs pass but the samples fail for precision or qualitative criteria (missing or poor internal standard ratio or peak shape) the samples (unknowns), fail and must be repeated in a new run and quantitation and acceptance based on the curve and QCs of the new run and not reflected back to the original run in which the sample failed.
Other assay values may be important in method development or problem solving regarding the assay or sample failure but they should not be considered as acceptance criteria. These other values may impact the linearity, accuracy and precision of the assay but they unnecessarily complicate the assay as extra processing not only for the analyst but also for QA and QC auditors and reviewers.
Avoid Excess Processing and KISS!