Statistical Quality Control
Building a Levey-Jennings chart by hand and judging a Westgard rule by eye is where quality control turns into wasted time and room for error. Here you log the control and the run comes back evaluated: the chart comes out automatically and the system tells you, flat out, whether to accept, warn or reject.
Control chart ready the moment you log the control.
You log the control and the Levey-Jennings comes out automatically, with mean and limits computed from your own data. No chart to build.
The system evaluates the run on its own and tells you: accept, warn or reject.
The system checks your run against the six Westgard rules (1-2s, 1-3s, 2-2s, R-4s, 4-1s, 10x) and gives back the call: accept, warn or reject. No staring at a graph trying to remember which rule was which.
Catches the small, sneaky drift that Levey-Jennings misses.
CUSUM (ISO 7870-4) tracks small, persistent drift, the kind Levey-Jennings lets slip. You set the parameters once and the system warns you when something is slowly going off.
Spots a trend early, with less noise.
EWMA (ISO 7870-6) reveals a trend by smoothing the noise, unlike Levey-Jennings. You see the pattern while other charts still say nothing. Tune the smoothing factor to your reality.
Control reagent expired? The system warns you in time.
You register the control reagent with lot, manufacturer, certified values and quantity. The system warns when it is near expiry and when it has expired. No expired reagent slips through.
Analysis deadline blown? The system warns you.
You set the analysis deadline per parameter and matrix (counted from collection, receipt or preservation). The system warns when it is about to expire and when it has, all tracked.
The limits come from your data, not a generic number.
Mean and standard deviation come from the controls you logged, so the chart reflects your process. No table limit that has nothing to do with your bench.
The decision to accept the run is recorded.
When the system accepts, warns or rejects, the verdict is saved alongside the run. At audit, the control history is not a spreadsheet someone could have edited afterward.
Three charts that see different things
Levey-Jennings alone does not see everything. That is why the system runs three approaches, each good at a different kind of problem.
Levey-Jennings with Westgard.
Catches the gross deviation and the rule violation on the spot: the error that jumps out on the graph.
CUSUM (ISO 7870-4).
Flags the small, persistent drift, the one that slowly slides off while the classic chart says nothing.
EWMA (ISO 7870-6).
Reveals a trend by smoothing the noise, so you see the pattern before it becomes a problem.
Frequently asked questions
Which Westgard rules are implemented?
All six: 1-2s, 1-3s, 2-2s, R-4s, 4-1s and 10x. You log the control and the run comes back with the call to accept, warn or reject.
Do I need to know statistics to use it?
Not to run the day to day. The chart comes out automatically and the system gives the verdict. CUSUM and EWMA you configure once and let work.
Does the chart use generic limits or mine?
Yours. The mean and limits are computed from the controls you logged, so the chart reflects your process, not a table number.
Does the system track control reagent validity?
It does. You register lot, manufacturer, certified values and quantity, and the system warns when it is near expiry and when it has expired.
Want to see the LIMS running with your lab's routine?
Book a demo and see it with your own data: the sample comes in by scanner, the QC comes back evaluated, the report comes out signed. No promises, you watch it work.