In a high-throughput mining lab, quality control is not a report you run at the end of the day — it is a decision you make on every batch. OnQC, the interactive QA/QC module in OnLIMS, collects, analyses and interprets control data in real time so problems surface while the run is still on the bench.
Accuracy and precision, watched live
- Accuracy charts Shewhart (default), Control X and Cumulative Sum (CUSUM) plot results against the mean and standard deviation — so drift is visible before it becomes a recall.
- Precision charts Range control, range ratio and percent replication track reproducibility — so a noisy method is caught early.
- Every QC type Standards (certified reference materials), controls, blanks and duplicates validate each analytical batch.
- Colour alerts A result over the limit turns the cell red; under the minimum, yellow — an immediate visual audit of the worksheet.
- Documented overrides Accepting an out-of-range value requires the analyst to record a note — so every exception is defensible.
Built into the run, not bolted on
Because QA/QC lives inside the same worksheet where results are captured, there is no separate export-and-check step. The analyst sees the control status next to the data, the supervisor reviews exceptions with their justification, and the laboratory keeps a complete, audit-ready QC record without extra administrative work.
Accuracy and precision in practice
Control charts are only as useful as the decisions they drive at the bench. OnQC turns each QC reading into an explicit accuracy or precision judgement and ties that judgement to whether a result can move forward for approval.
- Accuracy = bias vs the certified value When a certified reference material (CRM) is run, OnQC compares the measured result against the certified value to quantify bias, and plots it on the Shewhart, Control X or CUSUM chart so systematic drift away from the true value is visible across the batch.
- Precision = duplicate range Duplicate pairs feed the range control, range-ratio and Thompson-Howarth plots, while percent replication tracks how consistently the method reproduces — a widening duplicate range exposes a noisy method before it reaches the certificate.
- Out-of-limit alerts that block approval When a CRM, blank, control or duplicate falls outside its limits, OnQC raises a real-time alert and the affected results are held back from approval until an analyst records a justification note — so no out-of-limit batch is signed off silently.
- Captured across the whole instrument fleet Accuracy and precision data flow in from 150+ instruments integrated via serial (RS232) plus 25+ via file import — including AAS, ICP-OES/MS, XRF and LECO C/S — so the same QC rules apply no matter how a result was measured.
Related: ISO 17025 LIMS · Instrument integration
Frequently asked questions
Which control charts does OnLIMS support?
OnQC supports Shewhart, Control X and CUSUM charts for accuracy, and range control, range ratio and percent replication for precision.
What QC sample types can OnLIMS track?
Standards (certified reference materials), controls, blanks and duplicates, validated as part of each analytical batch.
How are out-of-limit results flagged?
In real time by colour: red when a result is over the limit, yellow when under the minimum, with a warning that requires the analyst to record a note before accepting it.
Is QA/QC separate from the analyst's worksheet?
No. QA/QC is interpreted inside the same worksheet where results are captured, so control status sits next to the data.