Student guide: Overview

The Overview is the app’s verdict on a laboratory.

The Overview is the app’s verdict on a laboratory. It looks at every analyte, check stage, CRM and blank in the data at once, and checks each against a rule. It then ranks what it found and sums up the laboratory in one word. Every result on the page comes from rules you can read and change, so this page covers the rules as well as the controls.

The Overview ignores the Filters, and the band is greyed out while you are on it. It uses both sheets of the file, the duplicates and the standards and blanks. The demo loads both. An upload needs a workbook with both sheets to fill every card, because a CSV holds only one or the other.

The app also reads a workbook that keeps its blanks on a separate sheet from the CRMs. A project stores them apart in the same way.

1. Lab Health: the header

Lab Health is the heading of everything from the top of the page to the Key Takeaway.

  • The pill Data up to despatch 34001 · 12/11/2025 shows the latest return date in either sheet, and the despatch most of that day’s results came in. It tells you how current the verdict is.
  • Results per month is a small chart of how many results came back each month. It shows when the project was busy and when nothing was sent.
  • Rules opens the window described in section 7.

Since last upload appears when you are signed in and open a project from Projects. If the project has more than one upload, this card under the header shows what the latest upload changed:

  • The lab jobs it added or replaced, sheet by sheet, and any laboratory, CRM or analyte seen for the first time.
  • Now failing or warning: checks that got worse, such as Warn → Fail or Pass → Warn, and new checks that start out failing or warning.
  • Improved: checks that were failing or warning and now pass or only warn.

The two lists fold away under one blue line with a ▸ in front, such as 104 checks now failing or warning · 7 improved. Click it to open them. Every blue line with a ▸ in the app works the same way.

Why: a new upload is the moment to act. The app checks both versions of the project against the rules in force now. A change in the list therefore comes from the data, never from a rule you changed. Data health is left out, because it belongs to the upload itself.

View opens the chart behind each row. If you take an upload out in Manage projects, the card disappears until the next upload.

2. The lab switch

There is one button per laboratory, each with a coloured dot and the laboratory’s confidence word. The demo has two, ALS and SGS.

The Overview opens on the laboratory with the newest data. Click another to switch, and everything below changes with it. If you change the Laboratory in the Filters while you are on another tab, the Overview follows that laboratory when you come back.

Why one lab at a time: every check compares results with that laboratory’s own history, its own despatches and CRM results. A bias at one lab says nothing about the other.

3. Lab Confidence and the headline

Lab Confidence is the verdict: High, Moderate, Low or Insufficient data.

Verdict Rule
Low One of the four domains fails: Accuracy, Precision, Contamination or Coverage.
Moderate None fails and at least one has a warning.
High Every domain that can be checked passes.
Insufficient data Neither CRMs nor duplicates can be checked. There is no CRM with a certified SD, and too few usable duplicate pairs.

A domain marked N/A has nothing to check, and it doesn’t count against the laboratory. SGS in the demo has no CRMs or blanks at all, so its Accuracy and Contamination are N/A. It is still Low, because Coverage fails.

Under the verdict, the headline is the laboratory’s single most serious finding. A failure comes before a warning. Within each, the order is CRM bias, duplicate precision, blanks, then coverage. So a CRM bias that has ended, which is only a warning, never hides a failing precision or blank check.

For ALS the headline is the Mo_MEICP41s_ppm bias, and for SGS it is the coverage failure, six months with no CRM or blank results. SGS’s duplicate precision is only a warning, so coverage comes first. The ? beside Lab Confidence sums up how each domain is checked.

You can soften this in Rules → Lab Health. A failing domain can give Moderate instead of Low, and a warning can give High instead of Moderate.

4. The domain cards

Four cards make up Lab Confidence. A fifth, Turnaround, sits beside them but doesn’t count towards it. Each card shows a status pill, a count, the worst finding, a note, and a button to the chart behind it. The pill reads Fail, Warn, Pass or N/A.

Accuracy (CRMs)

FAIL · 9 biased · 19 to watch · of 37 analytes Mo_MEICP41s_ppm: sustained negative CRM bias of −1.4 SD since despatch 17301 (16/09/2024). It covers 359 results over 114 despatches and is ongoing.

What it does. For every analyte, the app works out how many certified standard deviations each company CRM result is from its certified value. This is the result’s z-score. The app puts the analyte’s CRM results in date order and runs them through a CUSUM. This running sum grows while results keep falling on one side of the certified value, and resets when they don’t.

When the sum crosses the decision limit, the analyte has a bias excursion. The bias reported, −1.4 SD for Mo, is the mean z-score over the excursion.

Status Rule (defaults)
Fail (“biased”) The excursion is still going on in the latest despatches, and its mean bias is ±1 SD or more.
Warn (“to watch”) An ongoing bias smaller than 1 SD, or a bias that ended within the last 20 despatches.
Pass Neither.
N/A There is no CRM with a certified SD above 0.

The CUSUM uses a shift of k = 0.5 SD and a decision interval of H = 5 SD. The CUSUM method page shows the arithmetic.

Why a CUSUM and not a count of failures: a lab that reports a CRM 0.8 SD low every time never breaks the ±3 SD limit on a Shewhart chart. Yet the same bias sits in every one of its real samples. The CUSUM adds up those small, same-side differences until they can’t be chance. That is what sustained means in the message.

Company CRMs and lab standards. Company CRMs are the ones your project inserted, and lab standards are the laboratory’s own. The company CRMs decide the status. The note Lab standards: 16 biased · 23 to watch · of 110 analytes is for information only.

Lab standards decide the status only for a laboratory with no company CRMs. They are a weaker test, because the laboratory knows which samples are its own standards.

The note 2 analytes can’t be checked. They have no certified SD, or every result is at the upper detection limit. explains why the card counts 37 analytes, not every analyte in the data. A CRM certified above the method’s upper limit can only ever read at that limit, so its results are not measurements.

View CUSUM opens the worst analyte’s CUSUM on the Charts tab.

Precision (duplicates)

WARN · 0 over the action limit · 7 to watch · of 171 analytes and stages Ni_MEICP43_ppm (Pulverising Stage): duplicate precision is over the limit. The median RD is 19.8% in the last 20 despatches, against a 10.0% limit. It has been over since despatch 1152 (12/11/2023).

What it does. For every analyte and check stage, the app takes the usable duplicate pairs. A pair is usable when both results are present and its mean is at least 10× the detection limit. The app works out each pair’s absolute relative difference, |MPRD%|, which is the difference as a percentage of the pair’s mean. It then compares the median over the last 20 despatches with the stage’s limit.

Status Rule (defaults)
Fail (“over the action limit”) The median RD of the last 20 despatches is more than twice the stage limit.
Warn (“to watch”) The median is over the stage limit. Or it is at least half the limit and 20% or more worse than in the 20 despatches before.
Pass Neither.
N/A There are fewer than 10 usable pairs in the window.

The stage limits are the usual industry ones: ±30% for field duplicates, ±20% for coarse (crushed) duplicates and ±10% for pulp duplicates. The app matches a stage it doesn’t know by its name. “Pulveris” gives 10%, “crush” 20% and “field” 30%, and any other stage gets the general default of 20%. The Rules window shows which limit each stage in your data got.

Why the median, and why 20 despatches: one bad pair in a despatch is normal, and a median ignores it. Twenty despatches give enough pairs to check, in a window short enough to notice a change. The note 26 are worsening and 26 improving compares each analyte’s last 20 despatches with the 20 before.

Why a threshold of 10× LLD: near the detection limit, a difference of one unit in the last digit is a huge relative difference. Such pairs say nothing about precision, so they are left out. The Data tab counts how many pairs that removes.

View Rolling Median opens the RD Rolling Median chart for the worst analyte and stage. That chart draws exactly this calculation.

Contamination (blanks)

FAIL · 7 in the latest despatch · 5 to watch · of 33 analytes Ca_MEICP41s_pct: blank contamination in the latest despatch. There were 15 exceedances in the last 20 despatches, the last in despatch 32901 (10/11/2025). Exceedances are becoming more frequent.

What it does. A blank should report nothing. For every analyte, a blank result is an exceedance when it is more than 5× the detection limit above the blank’s certified value. A blank with no certified value is taken as 0.

Status Rule (defaults)
Fail An exceedance in the latest despatch.
Warn An exceedance in the last 20 despatches, or exceedances becoming more frequent.
Pass Neither.
N/A There is no blank with a detection limit.

Why 5× LLD: a blank reads a little above zero by chance, and the limit allows for that noise. A result five detection limits above it is metal that came from somewhere. It is carry-over from the sample before, or a contaminated crusher or pulveriser.

View Blanks chart opens the worst analyte’s blanks bar chart.

Despatch coverage

FAIL · No duplicate results from Feb 2024 to Jun 2024

What it does. It checks that the QC was actually sent. For every despatch of the laboratory it counts the duplicate pairs, CRMs and blanks.

Status Rule (defaults)
Fail For whole months the laboratory has duplicates but no CRMs or blanks at all, or the reverse.
Warn Some despatches have fewer than the minimum: 1 duplicate pair, 1 CRM, 1 blank.
Pass Every despatch has the QC the Rules ask for.
N/A The upload has only one of the two sheets.

Why this is a finding: QC that was never submitted can’t tell you anything. A gap of months usually means the project stopped inserting that QC, or the export left it out. It is rarely the laboratory’s fault. View data opens the Data tab on the period concerned.

Turnaround

WARN · 19 working days · median of the last 20 despatches · usually 17 Turnaround is slowing. The median of the last 20 despatches is 19 working days, against 15.5 working days in the 20 before.

What it does. For every despatch it counts the working days, Monday to Friday, from the send date to the last return date. A despatch can come back in parts. The card compares the laboratory with its own history, not with a fixed number. ALS’s usual turnaround, the median of its despatches before the latest 20, is 17 working days.

Status Rule (defaults)
Fail The median of the last 20 despatches is more than 1.5 times the lab’s usual.
Warn That median is 20% or more, and at least a day, longer than in the 20 despatches before. Or the latest despatch took longer than 90% of the lab’s despatches.
Pass Neither.
N/A Fewer than 10 despatches have both a send and a return date. SGS in the demo has 3.

Public holidays count as working days, because the app doesn’t know which country each laboratory works in. A despatch missing either date, or returned before it was sent, is left out. Data health lists those rows.

Why it isn’t part of Lab Confidence: Lab Confidence is about whether you can rely on the results. A slow laboratory delays drilling decisions and reports, but its results can still be good. Turnaround has its own card so you can raise it with the laboratory without making the results look worse than they are.

View turnaround opens a chart of every despatch, with its working days against the date returned. A line shows the median of the last 20 despatches. Green marks the lab’s usual, amber its slowest 10%, and red the fail level for the median. Point at a despatch to see its dates and number of results.

5. Key Takeaway, Current Risks and Worst analytes

Key Takeaway sums up the four cards in one paragraph. It gives the main concern first, then what else needs watching, then what is fine and what can’t be checked.

Current Risks lists every failing and warning check for the laboratory. Failures come before warnings, and then the checks are ranked by how many results they affect. The demo’s ALS has 381.

Each row gives the finding, its context, the despatch and the number of results. The context is the bias the finding is part of, or the trend.

  • Investigate on a failure and Review on a warning open the chart behind the check, with the Filters set. A duplicate finding opens the Scatter chart, with the check stage’s RD limit as its control lines. The red pairs are the ones outside the limit.
  • View data opens the Data tab, for coverage findings and Data health warnings.
  • The list shows five rows. Show the next 35 reveals more, up to 40.

These rows come from a second, simpler set of checks that look at the latest results rather than trends:

Check Fail Warn
CRM (per CRM and analyte) The latest result is beyond ±3 certified SD. An earlier result went beyond 3 SD, 2 of 3 consecutive results were beyond 2 SD on one side, or 9 in a row fell on one side.
Duplicates (per analyte and stage) More than 20% of usable pairs are outside the stage limit. More than 10%.
Blanks (per blank and analyte) The latest result exceeds the limit. An earlier one did, and the latest is clean.

So the single result Mo_MEICP41s_ppm: the latest EXP-3 result is 9.0 SD below certified sits beside the trend, sustained negative CRM bias of −1.4 SD. Both are true. The first is what you would see on a Shewhart chart, and the second is what the CUSUM found.

Worst analytes is a table with one row per analyte that has a warning or failure. For ALS it shows 34 with a warning or failure · 51 clear · 39 can’t be checked. Its columns are:

Column Meaning
Accuracy (CRM bias) The mean bias since the CUSUM first crossed its limit, and whether it is ongoing or ended.
Precision (median RD / limit) The check stage that is worst against its limit over the last 20 despatches. For Al it is 5.8% / 20% at the Crushing Stage.
Blanks (exceedances) How many of the last 20 despatches had one.
Trend Bias since 13/10/2025 · Precision worsening · Blanks more frequent, or Steady.

Click any value to open its chart. The table shows ten rows, and Show all 34 reveals the rest.

Example. Al_MEICP41s_pct heads the ALS table. It has an ongoing CRM bias of +1.3 SD, and crushing-stage precision of 5.8% against a 20% limit, which is fine but worsening. Its blanks were contaminated in 12 of the last 20 despatches. These three problems point to three different causes: a calibration drift, a crushing problem, and carry-over.

7. The Rules window

Rules opens Rules and how checks work. Each section has its fields on the left, the rule in plain English on the right, and a Reset to defaults button.

Apply saves only what you changed, with your account when you are signed in and otherwise in this browser. The Lab Health header then shows a Custom rules pill naming what differs. Reset all returns everything to the defaults.

Section Fields and defaults
Analytes to assess Up to 5 analytes. Leave all at (none) to assess every analyte. Use it to focus the Overview on the elements that matter to the project.
Lab Health CUSUM shift k 0.5 SD, decision interval H 5 SD, ongoing bias fails from ±1 SD, trend window 20 despatches and trend change from 20%. Lab Confidence is Low when a domain fails and Moderate when one has a warning.
Precision The RD limit for each check stage in the data, with its pair count and where the limit came from. The limit for any other stage is 20%. Pass when at least 90% of pairs are within the limit, and warn from 80%. A usable pair’s mean is at least 10× LLD, and at least 10 usable pairs are needed.
Accuracy (CRMs) Fail beyond ±3 certified SD, with a warning zone from ±2. Nine consecutive results on the same side are a warning.
Contamination (blanks) Fail when above certified by more than 5× LLD.
Despatch coverage Each despatch needs at least 1 duplicate pair, 1 CRM and 1 blank. Each can be set from 0 to 5, where 0 means not required.
Turnaround The recent median fails above 1.5 × the lab’s usual. A slow despatch is longer than 90% of the lab’s despatches. At least 10 despatches need both dates. The window and the 20% change are set under Lab Health.
Featured charts The chart on each Overview card.
Data health Not adjustable, because these are errors in the data, not tolerances.

Why the rules are visible: a QC verdict compares results with limits, and the limits are a choice. Your project’s QA/QC plan may allow pulp duplicates ±15%, or treat a bias of 0.5 SD as serious for gold. Set the rules to match the plan, and the Overview checks against the plan.

Example: tightening the bias rule. Set Ongoing bias fails from to 0.5 SD and click Apply. Analytes with a bias between 0.5 and 1 SD were “to watch” before and now count as biased, so the Accuracy card’s numbers change. The Custom rules pill reads 1 changed, and the Rules window names the change: Ongoing bias fails from (± SD): 0.5. Reset all puts it back.

Exercises

  1. What makes ALS Low? List the four domain statuses and say which of them would make Lab Confidence Low on its own. Then open Rules → Lab Health and change Lab Confidence when a domain fails to Moderate. What is the verdict now, and is that a sensible rule for a real project?
  2. Trend or event? In Current Risks for ALS, find the Mo_MEICP41s_ppm rows. One says the latest EXP-3 result is 9.0 SD below certified. Another says there is a sustained bias of −1.4 SD since 16/09/2024. Explain the difference between the two checks, and why a laboratory could fail one without failing the other.
  3. The threshold. Open Rules → Precision and change Usable pair: mean at least (× LLD) from 10 to 2. Watch the Precision card. How do the counts of analytes and stages, and the “to watch” count, change? Why does a lower threshold make precision look worse?
  4. Missing QC. Switch to SGS. Its Accuracy and Contamination are N/A, yet its Lab Confidence is Low. Which card is responsible, and what would the project, rather than the laboratory, have to do about it?
  5. A slow laboratory. On the ALS Turnaround card, open View turnaround. Find the slowest despatch on the chart. How many working days did it take, and does one slow despatch move the median line much? Then explain why the card warns when the median of the last 20 despatches is longer than in the 20 before, rather than for every despatch over the usual.
  6. Your own limits. Suppose your project’s QA/QC plan allows pulp duplicates ±15% and crushed duplicates ±25%. Set those limits in Rules → Precision for the Pulverising and Crushing stages, and apply them. Note how the Precision card changes: its “to watch” count, and which analyte now leads it. Does Ni_MEICP43_ppm still count as over the limit? Then click Reset all.