“It’s in spec, so it’s fine.”
The drawing judges one part. The chart judges whether the process has changed. A point beyond the control limit inside the tolerance is the early warning the chart exists for, and it’s the one most often ignored.
Lean Six Sigma path · SPC1 · Self-paced
Plus four isn’t the problem.Chasing it is.
A bracket reads plus four microns, well inside the drawing. The machinist reaches for the offset to bring it back to nominal. It feels like good machining. On a stable process, it makes the next hundred parts spread wider. Learn to read a control chart the way the floor needs to: when to leave it alone, what to do when it signals, and when a capability number is worth sending.
For machinists, operators, setup techs, inspectors, cell leads and supervisors who keep or read control charts. No statistics background needed: the arithmetic is averages, ranges and a few constants from a table.
- About 6 to 7 hours planned
- Six modules + practical labs
- No statistics background
- Fictional shop, real sources
- Person-scored case
16:20 at a fictional machine shop
“Plus four. I’ll take four off the offset so the next one lands on nominal. Two seconds.”
- Is plus four normal for this machine?
- What would actually tell you it changed?
- If it did change, which parts are in doubt, and who decides?
Your site’s procedures, reaction plans and customer requirements decide what you do at work. The course teaches you to read and use them well.
Inspect the six work tools →Try the course first
Read the process, not the part.
Open the real first lesson with Coach Q. Sort spec limits from control limits, read a shift’s chart, and see what happens to the spread when someone adjusts after every reading.
Enter your name, work email and phone, then verify your email to open lesson 1. No payment card is required.
Every shop, person and reading in the course is fictional and labeled as such.
Sound familiar?
The chart is on the machine. Nobody trusts it.
Most shops that chart have the same four habits. Each one quietly turns the chart into wallpaper.
“I keep it on nominal.”
Adjusting after every reading feels careful. On a stable process it adds each reading’s noise to the next part. Over the long run the standard deviation grows by about the square root of two, roughly 41 percent.
“Our chart never goes out.”
Sometimes that’s because every subgroup mixes two fixtures, spindles or cavities. The limits widen until nothing can cross them, and a real drift goes unseen.
“Just recalculate the limits.”
New limits that make a signal go away hide the very thing the chart was built to show. Limits move only after a deliberate, approved change, never because a chart got inconvenient.
See the method · fictional teaching example
Two notes about the same signal. Only one helps.
At fictional Kestrel Precision, VMC-1’s 16:00 subgroup averaged +8.08 microns, beyond its upper control limit of +5.45. Every bracket was inside the drawing. Two people sent the supervisor a note.
Note A
Sounds decisive.
“Bores ran big, so I knocked 8 off the offset. Next five are dead on. We’re good to ship the hour.”
Nobody knows the cause, the offset change is now mixed in with whatever moved, and the brackets made before the change are about to leave with nobody deciding on them.
Note B
Says what’s known, and what isn’t.
- 16:15 plotted: average +8.08, beyond the UCL. Rule K1.
- 16:20 gauge zeroed on its ring, re-measure agrees.
- Held: 33 brackets, 15:10 to 16:16, tagged on the hold rack.
- Bar lot changed at 15:40: a lead, not yet a cause.
- Quality to decide on the held brackets through an NCR.
Open what happens next
Note B goes to the supervisor and the quality engineer, as the reaction plan names. The limits stay where they are, nobody ships the held brackets on a hunch, and the cause search starts from the records instead of a guess.
In the course you count that hold yourself, test each claim against the records, and a person scores your independent case against the same standard.
From reading to report
Six habits you can use on your own floor.
Read the process → collect data the chart can see → build limits from the data → read every rule → stop, check, hold, then fix → report only what the chart supports. Each module ends with a tool you can take to work on Monday.
- 01 Read
- 02 Collect
- 03 Build
- 04 Spot
- 05 React
- 06 Report
The rule on one card.
A point inside the limits that breaks no rule is common-cause variation: leave the offset alone and plot the next one. A signal gets the reaction plan, starting with the gauge, and everything made since the last good subgroup waits for the person your procedure names.
Control limits come from the process’s own data, never from the drawing, and a signal is never a reason to recalculate them.
Kestrel’s rule set and reaction plan are a fictional site’s choices. Your site’s procedures decide.
What you can say at the machine
“Leave it. Plus four is inside the limits and breaks no rule. Plot it and run the next one. If the chart signals, we stop and check the gauge first.”
From the course’s first module. In its simulation, adjusting after every reading widened the spread from 3.0 to 4.1 microns.
What you bring back
Six tools for Monday morning.
Build them in the labs at a fictional machine shop, then use the blank worksheets for the charts at your own work, with information your company allows you to use.
Before you touch the offset
Every time you measure. The right move for four kinds of reading: inside the limits, beyond a limit but in spec, out of spec on a quiet chart, and a run of eight. Who you tell for each.
Data collection plan
Before you start a chart. The characteristic and spec, the gauge and when it’s checked, how parts are picked so each subgroup holds one stream, how often, which charts, and what gets written on them.
Control limits record
When a chart is set up or reset. The data used, the center lines, the constants, the limits, any signals in the trial data, who approved them and when, and what’s allowed to change them.
Signal card
At the machine, every shift. Four rules, what each looks like, what it often points to, and the first question to ask before anyone touches the process.
Reaction record
When the chart signals. The rule and the time, the gauge check, what’s held from when to when and how many, who was told, the cause or what’s still open, the correction and the owner who decides.
Chart review card
Every week, and before any number leaves the building. Stability, signals and how each closed, limits and their approval date, capability only if stable, the AI or spreadsheet output checked, and open actions with owners.
Is this the right course?
For the people at the machine, not just the people in the office.
A good fit if you…
- Measure parts and plot them, or are about to start.
- Lead a cell or a shift where charts hang on the machines.
- Set up or audit charts and want the floor to trust them.
- Get asked for a Cpk and want to know when it means something.
No statistics background is needed. The arithmetic is averages, ranges and constants from a table, done by hand once so you know what the spreadsheet is doing.
Not what this course is
- A full measurement system study course (see Measurement Systems and Gage R&R).
- Short-run, EWMA, CUSUM or multivariate charts, or non-normal capability.
- Your customer’s own SPC manual or requirements.
- Authorization to set or approve limits, or to release product.
Your site’s procedures and your customers decide those. The course makes you the person who reads the chart right and asks the right questions.
Inside the course
The course, step by step.
About 5 hours, self-paced, in short sessions that fit your week.
Read the process, not the part
Tell normal variation from a signal, and know when not to touch the process. 2 lessons.
Collect data the chart can use
Plan subgroups and measurements so the chart can see a real change. 2 lessons.
Build the chart
Choose the right chart and work out its limits from the process's own data. 2 lessons.
Read the signals
Spot a signal with the site's rule set, including the ones that never cross a limit. 2 lessons.
React to a signal
Work a signal through the reaction plan, contain the right parts and record it. 2 lessons.
Prove capability, and check the AI's chart
Report capability only from a stable process, and catch the errors in an AI-drafted chart summary. 2 lessons.
Inside the course
Six modules, one fictional shop, two weeks of charts.
Each module pairs a guided lesson with a hands-on lab, a narrated explainer, a method card and a coached reflection. Then you apply it to an unseen case at a different shop.
01 / 06
Read the process, not the part
Plus four. Fix it?
Spec limits judge a part. Control limits judge the process. Learn why a part can be in spec and still be a signal, and why moving the offset after every reading makes the bores spread wider.
- Practice: Read a shift’s chart point by point and talk a skilled machinist out of chasing nominal.
- Take forward: Build your "Before you touch the offset" card.
02 / 06
Collect data the chart can use
Twenty quiet hours.
Check the gauge first, then group parts so each subgroup holds one stream. See how two fixtures in one subgroup blinded a chart while one of them drifted for seven hours.
- Practice: Work out the limits both ways, fix the sampling plan and make the case to the quality engineer.
- Take forward: Write the data collection plan.
03 / 06
Build the chart
Where do the limits come from?
Pick the chart from the data. Work out X-bar and R limits by hand once, approve them, fix them in place, and keep spec lines off the averages chart for good.
- Practice: Build a machine’s limits from 20 subgroups and answer an AI draft that wanted the tolerance as limits.
- Take forward: Fill in the control limits record.
04 / 06
Read the signals
Thirty points, none outside.
Zone lines and four rules. Spot the signal that never crosses a limit, and learn why every extra rule adds false alarms.
- Practice: Open a night-shift chart point by point, find where the rule fires and write the handover note.
- Take forward: Fill in your signal card.
05 / 06
React to a signal
Friday, 16:15, truck at 18:00.
Stop, check the gauge, hold everything since the last good subgroup, write it down, find the cause, then fix only what the cause shows. The named owner decides on held parts.
- Practice: Count the hold, test claims against the records and hold the line with a plant manager and a shipping list.
- Take forward: Write the reaction record.
06 / 06
Prove capability, and check the AI’s chart
The AI says 2.45.
Capability only means something on a stable process. Work out Cp, Cpk and Ppk, then read an AI-drafted summary line by line against the records.
- Practice: Catch four errors in an AI summary and write a capability note a customer can trust.
- Take forward: Fill in the chart review card; put it beside your first call.
The learning experience
Practice the calls before the truck is waiting.
01 · Practice
Decide, then see what happens.
Branching conversations with a machinist chasing nominal, a supervisor two people short on second shift and a plant manager with a shipping list show the consequence of each answer. Five teaching diagrams, seven short narrated videos with captions and transcripts, and ten scenario photos carry the lessons.
02 · Reflect
Connect each module to your own floor.
A coached reflection closes every module. Six worksheets and Course Hub document tools let you build your own card, plan, limits record, signal card, reaction record and review card.
03 · Apply independently
Show it on a fresh case.
One assigned case from three fictional shops, six decisions and a separate 30-question exam. A person scores your case.
Practice support that makes you do the thinking.
Coach Q is QMS Learning’s AI quality and compliance colleague. In practice it asks what the chart shows and which rule applies, and gives hints that get more specific. It won’t do your arithmetic, decide on held parts or approve limits. Those belong to the people your site names.
Coach Q’s default allowance is 40 messages per rolling 24 hours. During the independent case and the exam, support is limited to navigation.
Illustrative practice exchange
“My last reading was plus six. Should I adjust?”
“What are your control limits? Is plus six inside them? Check it against each rule on your signal card. If none fires, what does the course say to do with the offset?”
AI suggestions can be wrong. Your site’s procedures and qualified people decide.
Course Hub keeps your study plan, focus timer, progress, Documents and Apply at work tracker together.
Plan about 6 to 7 hours, self-paced. The 403-minute planning estimate includes an 8-minute first attempt, six modules of 45 to 55 minutes, a 45-minute case, 20 minutes of decisions and a 30-minute exam. This is a planning estimate, not a measured completion time.
Why pay for structured practice?
A chat app will tell you the formula for a control limit. That’s not the hard part.
The hard part is the reading in front of you: leave it, or act? And when you act, what do you hold, who do you tell, and what do you never touch? That’s judgment, and judgment comes from practice on realistic charts with feedback.
What the course is designed to add
- Decisions on realistic charts, where the obvious answer is often wrong.
- Every number worked by hand once, so the spreadsheet stops being a black box.
- Named sources: the NIST/SEMATECH e-Handbook, ISO 7870-2:2023, ASQ and Minitab.
- An unseen case scored by a person, and a separate exam.
What it won’t pretend to do
It doesn’t replace your site’s reaction plan or your customer’s SPC requirements, and it doesn’t authorize you to set limits or release product. It makes you the person who reads the chart right and gets the right people moving.
What informs the teaching
Real sources, a fictional shop.
Every shop, person, reading and chart in the course is fictional, and the data is generated for teaching. The methods come from these sources, checked October 2026:
- NIST/SEMATECH e-Handbook of Statistical Methods, section 6.3: control chart formulas and constants, the Western Electric rules and their false-alarm cost.
- NIST/SEMATECH e-Handbook, section 6.1.6: process capability, Cp and Cpk.
- ISO 7870-2:2023, Shewhart control charts (the course cites its public abstract, not its text).
- ASQ, Control Chart and Minitab, Cpk vs. Ppk.
Sources inform the teaching. They don’t endorse the course.
How you earn assessed completion
Earn the record by showing your judgment.
- Complete the required labs and coached module reflections.
- Pass the person-scored independent case at 16/20 and decisions at 10/12, with no unresolved critical error. Releasing suspect parts without the named owner’s decision, recalculating limits to make a signal go away or setting them from the spec, adjusting on a point that breaks no rule, or claiming capability for an unstable process is a critical error.
- Pass a 30-question final exam at 24/30 (80%). You have three exam attempts, with a 24-hour wait after an unsuccessful attempt.
Contact will@qmslearning.com about case review or revision. No fixed review turnaround is promised.
The verifiable certificate records what you showed in the course. It isn’t a license, an accreditation or your employer’s authorization to set limits or release product.
The itemized offer
Everything included, before the price.
Structured practice, six work tools, coaching and independent assessment. No invented component values, former prices or savings.
Your complete course package
Six-module course and practical labs
IncludedGuided lessons, branching conversations, chart and data decisions and coached reflections at one fictional machine shop. Seven synthetic-narrated videos with captions and transcripts, five teaching diagrams and ten scenario photos.
Six worksheets and document tools
IncludedBefore-you-touch-the-offset card, data collection plan, control limits record, signal card, reaction record and chart review card.
Coach Q for practice
IncludedCourse-aware practice support that asks what the chart shows and never does your arithmetic, default 40 messages per rolling 24 hours. Navigation only during the independent case and exam.
Person-scored independent case
IncludedOne assigned case from three fictional shops (an X-bar chart on a lathe, a p chart on burr rejects, three lathes on one chart), scored by a person against a five-part rubric with critical errors. Six decisions are assessed separately.
Final exam and assessed completion
IncludedA 30-question exam with a 24/30 pass mark; three versions support three allowed attempts, with a 24-hour wait after an unsuccessful attempt.
Course Hub, study and application tools
IncludedStudy plan, focus timer, saved progress and the Apply at work tracker.
Complete course · US dollars · per named learner
$149 one-time course price
Lifetime lesson access with no course subscription. Coach Q and AI tools follow the accepted usage and service terms; this isn’t unlimited coaching or a promise of perpetual AI service. Applicable tax is shown at checkout.
People
Enroll for $1495 or more people get 10% off every seat. One-time purchase. 3-day refund under Academy policy.
Each seat belongs to one named learner. Choose 1 to 50 people. Five seats total $670.50 before applicable tax after the 10% seat discount.
Make an informed decision
Bring it to your manager.
Before purchase
Try the first lesson.
Use the real guided lesson with Coach Q and decide whether it fits your floor. Start lesson 1 free ↑
For an individual Academy course purchase, request a refund within 3 days, subject to the Order. A refund ends access and invalidates a completion certificate. Read the full refund policy.
If your company pays
Use a concrete training request.
Request a quote or PO arrangement. This opens your email application; nothing is sent by this page.
Straight answers
What to know before you commit.
Who is this for?
Machinists, operators, setup techs, inspectors, cell leads and supervisors who keep or read control charts, and quality technicians who set them up.
Do I need a statistics background?
No. The arithmetic is averages, ranges and a few constants from a table. You do it by hand once so you know what your spreadsheet or SPC software is doing.
Which charts does it cover?
X-bar and R, individuals and moving range, and how to choose between them and X-bar and S, p and c charts. It also covers rational subgroups, the Western Electric rules, reaction plans, and Cp, Cpk and Ppk.
How is this different from the Green Belt?
The Green Belt takes a whole improvement project from problem to proven fix; SPC is one piece of its Control phase. This course goes deeper on running and reacting to charts at the machine, for the people who do it every shift.
Does it cover gauge studies?
It shows why the gauge gets checked before any point is trusted. For full measurement system studies, see Measurement Systems and Gage R&R.
Will it make me compliant with my customer’s SPC requirements?
No course can promise that. Your customer’s requirements decide which charts, rules and capability indices apply. The course teaches the methods underneath them.
Can Coach Q do the assessment for me?
No. During the independent case and exam, support is navigation only.
What do I need to pass?
Complete the required labs and coached reflections; score at least 16/20 on the person-scored case and 10/12 on decisions with no unresolved critical error; and pass a 30-question exam at 24/30 (80%).
What if I don’t pass first time?
You have three exam attempts, with a 24-hour wait after an unsuccessful one. Case review feedback and any revision go through the reviewer; contact will@qmslearning.com with questions.
How long does it take?
Plan about 6 to 7 hours, self-paced. This is a planning estimate.
How long do I keep access?
A one-time purchase gives lifetime lesson access without a course subscription, under the accepted terms. Coach Q and AI tools stay subject to usage and service terms.
What is the refund policy?
For an individual Academy purchase, request a refund within 3 days; the Order controls if it says otherwise. Email will@qmslearning.com with “Refund Request” and your checkout email. A refund ends access and invalidates any certificate for the course.
Is the certificate a license or accreditation?
No. It records what you showed in the course. It isn’t a license, an accreditation or your employer’s authorization.
Can my company buy seats or use a PO?
Yes. Choose 1 to 50 named learners. Five or more seats get 10% off each seat; five seats total US$670.50 before tax. Contact will@qmslearning.com for a quote or PO.
Can I try a free lesson?
Yes. Enter your name, work email and phone, then verify your email to open lesson 1 with Coach Q. No payment card is needed.
Be the one who reads it right
Leave the noise. Catch the signal. Hold the right parts.
Know what the chart is telling you, and what to do about it.
- Tell a normal reading from a signal, and leave a stable process alone.
- Sample so the chart can see, and build limits from the data.
- Spot signals that never cross a line, and work them through the reaction plan.
- Report capability only when the chart supports it.
Six tools. The chart, used properly.
Six modules, seven captioned narrated videos, five diagrams, ten scenario photos, six worksheets, practice coaching, a person-scored case and a separately passed exam.
$149 per named learner, one time. About 6 to 7 hours planned. Lifetime lesson access; AI usage and service terms apply.
Enroll for $1493-day refund under Academy policy. Certificate eligibility requires passing all required work.