u/SimplicityHub

We have trained continuous improvement teams for a living, and every so often a story comes along that explains root cause analysis better than any textbook we could write. This is one we tell a lot.

A manufacturer had a labelling machine on Line 2 that kept jamming. Maintenance did the sensible things — swapped the sensor, then the feed motor, recalibrated twice. Three weeks, a stack of parts, the line down repeatedly. Every fix "worked" until it didn't.

It's the classic trap, and honestly most teams fall into it: they treated the point where the symptom appeared as the place the problem actually lived. The machine was where it showed up, so the machine got the blame.

What broke the loop was one question from a newer team member at standup: "Does it only jam on certain days?" Nobody had looked. So they plotted it — and it jammed almost every Tuesday and Thursday morning. Nothing else correlated. Not shift, not operator, not product, not batch.

Turns out Tuesday and Thursday were the early cleaner's mopping days for that end of the floor. Floor still damp at first shift, someone props the side door open to air it out, the draught lifts the edge of the label stock as it feeds, and it jams. They fixed it by moving the mop rota and stopping the door-propping. Cost: nothing. It hasn't jammed since.

Here's the part we always land on when we teach it: the team had all the data to solve this on day one and didn't, because nobody went and watched. They stood at a screen reading the maintenance log — which only records what got replaced, never when the fault actually fired — and pattern-matched off the wrong dataset. Fifteen minutes at Gemba would have caught the damp floor.

The lesson we drill into every team we work with is dead simple: you don't get to touch a part until you can say when the fault happens, not just what failed. Five whys, sure — jam, damp floor, mopping rota, no owner for morning cleaning, no standard work for it. But the whys only work if the first answer comes from the floor, not the log.

So we'll put it to this sub, because between you all there are far better ones than ours: what's your "it was the mop" story — the fault your team threw parts and downtime at, where the real cause turned out to be something human and unwritten that a few minutes at Gemba would have caught?

Something we see constantly on the floor: a line's got a quality or output problem, so someone starts tweaking. Change one setting, run a batch, measure. Change the next, run another, measure. One factor at a time. Feels rigorous. It's actually the slow, blind way to do it — and it completely misses the thing that usually matters most: interactions.

That's what Design of Experiments (DoE) fixes. Instead of testing factors one by one, you test them together in a structured way — so you learn more from fewer runs, and you catch when two settings only cause a problem in combination.

Quick example. Say you're running a machine that fills and seals packets, and you're getting too many bad seals. You reckon it's down to two things: conveyor speed (slow vs fast) and sealing temperature (low vs high).

- One-factor-at-a-time: fix the speed slow, test both temperatures, pick a winner, then go back and test speed. Six-plus runs and you still don't know whether speed and temperature affect each other.
- DoE (a simple 2×2 factorial): run all four combinations —
- slow speed / low temp
- slow speed / high temp
- fast speed / low temp
- fast speed / high temp

Four runs. Now you can see not just "higher temp = better seals" but "higher temp only works when the line's running slow" — that's an interaction, and OFAT physically can't reveal it. That's usually where the real defect reduction is hiding.

And it scales: 3 factors in 8 runs, and you still get main effects and interactions. It's the difference between guessing and knowing.

Anyway — has anyone here actually run a DoE on a live line? Curious what factors you tested and whether any of the interactions genuinely surprised you. The textbook cases are always tidy; real processes never are.

If anyone wants to reveal how much of your total lead time is actually adding value vs sitting in queues, waits and rework check out our free process cycle efficiency calculator: https://www.simplicityhub.co.uk/pages/pce.html

Different kind of post today all, we wanted to open up the topic of why we exist and what we can do for you as a community!

Over the many many years as team of CI professionals we have encountered professionals at all levels and one thing that saddens us is when people or organisations complete training and become certified in Lean or Lean Six Sigma but then never use the skills they have gained.

We have been looking and there are hundreds of providers out there offering lean six sigma training but when you come away from it passing an exam and feeling great you don’t know what the next steps are.

So we went a step further firstly we made sure our content was written by a Lean Six Sigma Master Black Belt with real life experience turning organisations into Lean environments, improving morale and saving millions in the process.

Next we ensured our Yellow, Green and Black belt courses all have projects you work through using the tools at that belt level and built in statistical calculators to get a hands on feel for how to use the skills in real life.

We have videos for 90% of our lessons so it’s not just reading words the whole way through. You also have an AI coach the whole way through you can ask questions of.

The exams are unlimited retakes and the material is lifetime access.

So then you pass the exam and we ensured you have over 80 templates you can download in multiple formats for free with examples of what good looks like in each. 25 statistical calculators to use for free whenever you need to. We’ve also published a 354 page Ultimate DMAIC playbook that has every template and calculator example in including yellow, green and black belt projects to understand and some history too. You get this book as part of the course at the moment.

We have spent time and effort creating over 350+ continuous improvement videos and it has been amazing to get over 1 million views so far, we really are trying hard to give the community everything you need to be a CI professional.

So we’d like to hear from you, what are we missing and what else is valuable to you that we can offer? 90% of our resources are free as we believe in making CI affordable for all.

Green belt seems to be the course that the majority needs at the moment. If anyone is interested in this or yellow or black belt have a look at :

https://www.simplicityhub.co.uk/pages/ultimate-DMAIC-playbook-promo.html

You’re probably thinking yeah you cost a fortune but all this is the same as the price of 4 cups of high street coffee!! You get the 354 page PDF version of the book, the course, exam and certificate, no extra charges. The money goes straight back into site improvements.

For those of you that need a flavour of lean or lean six sigma we have 3 free courses yes free no hidden charges or certificate payments entirely free, lean six sigma white belt, lean fundamentals and root cause analysis associate. Go grab your 3 certificates for your CV for free and all the free tools and resources.

If you’re a charity get in touch, you get EVERY course and resource for free, no charge at all, we believe in supporting charities and they can teach us all a thing or two on how to streamline processes as they run businesses very lean at minimal costs so these tools and skills will only strengthen the ability to work efficiently!

Keen to hear what else we can offer you all, thanks for taking the time to read this.

SimplicityHub**®**

Been running CI projects across a few different environments and started keeping proper notes on where time gets spent at each DMAIC phase. After 6 projects I had enough data to see a pattern — and it surprised me.

The common assumption is that Analyse takes the longest. It doesn't.

In my experience it goes like this:

Define — longer than it looks.
The problem statement alone eats 2–3 weeks in most organisations. Getting stakeholder sign-off on scope is where projects quietly die before they start.

Measure — the hidden black hole.
Everyone underestimates data collection. Systems that "should" have the data don't. Manual workarounds add weeks. This phase consistently ran 40–60% over estimate in my projects.

Analyse — actually the fastest.
Once you have clean data, the stats are quick. Fishbone, regression, hypothesis testing — this is where it *looks* complex but moves fast if Measure was done properly.

Improve — fast to decide, slow to implement.
Pilot runs, change management, sign-offs. The solution is rarely the bottleneck. Getting people to adopt it is.

Control — where projects go to die quietly.
Control plans get written and filed. Nobody reads them 6 months later. This is the phase most organisations rush because they've already celebrated.

The biggest time sink across all 6? Waiting. Waiting for data access, waiting for meetings, waiting for approvals. Nothing in the DMAIC toolkit fixes organisational friction.

Curious if this matches what others are seeing — particularly whether Measure is as painful for everyone else as it was for me.

We have blogs that may also be of interest to check out: www.simplicityhub.co.uk/pages/blog.html

Been reflecting on projects I've seen stall or get shelved over the years.
In my experience the failure usually happens in one of three places:

1. The problem statement is too vague — the team ends up solving the wrong thing

2. No real sponsor — the project hits political resistance and dies quietly

3. Jumping straight to solutions before the Measure phase has said anything useful
   Curious what patterns others have seen.

What's the most common failure mode in your organisation?

Been digging through keyword/search-volume data for Lean Six Sigma topics (nerdy rabbit hole, I know) and a few things jumped out that I think this community would find genuinely useful:

1. "Six Sigma vs Lean Six Sigma" gets searched way more than I expected.
Turns out a huge chunk of people entering this field don't actually know these aren't the same thing — Six Sigma is the statistical/defect-reduction side (DMAIC, control charts, DPMO), Lean is the waste/flow side (VSM, 5S, kaizen). "Lean Six Sigma" is just the industry mashing both together because in practice you use tools from both anyway.

2. Cpk and DPMO calculators get searched constantly, but most of the results online are either paywalled or sign up for downloads.
If you've ever had to explain Cpk vs Ppk to a manager who glazes over at the word "standard deviation," you know the pain. There's clearly demand for something that just... works, for free, without a login wall. (Put together 25 free ones here if it's useful to anyone: https://www.simplicityhub.co.uk/pages/tools.html)

3. "Black Belt project ideas" is searched a lot, but there's barely any real content answering it.
Everyone wants example projects to reference before starting their own. Feels like a gap — most Black Belt resources jump straight to theory and skip "okay but what does an actual finished project look like."

4. Root cause analysis (fishbone/5-Why) content is everywhere, but almost none of it uses real numbers.
Lots of generic templates, very few worked examples with actual before/after data. If you're studying for an exam or trying to convince a skeptical stakeholder, seeing real numbers matters way more than another blank fishbone diagram. (Have a set of 80 blank all with filled-in examples, templates here if anyone wants a starting point: https://www.simplicityhub.co.uk/pages/templates.html)

Anyway — mostly sharing because I think it says something about where this field still has gaps (especially free and practical resources vs. theory-heavy content). Curious if others here have noticed the same thing — do you feel like there's a lack of practical/example-based content for this stuff, or am I just deep in a research hole at 10am on a Thursday?

Hey everyone, I spend a lot of time looking at the CI, Lean, and Six Sigma job market across the UK/Europe, and the landscape is shifting pretty quickly. I have a full
Write up you can check out at the bottom, a few things I’m seeing consistently:

1. The 'Green Belt' bottleneck:
   Roles requiring a Green Belt are staying open way longer than average. Companies are desperate for people who can actually *run* a project independently, and basic White/Yellow belt awareness just isn't cutting it for hiring managers anymore.

2. The fastest growing sector isn't manufacturing:
   Financial services seems to be aggressively hunting for Lean Six Sigma practitioners right now.

3. The AI + CI hybrid premium:
   The highest-paying roles are starting to specifically ask for practitioners who know how to integrate AI tools into the DMAIC cycle (especially for data crunching during the Analyse phase).

Has anyone else noticed this shift in their own industries? Would love to hear what you're seeing out there.

PS: I put together a broader write-up on where I see the CI industry heading this year on my site here:

https://www.simplicityhub.co.uk/reports/lss-uk-report-2026.html

Hey everyone, I spend a lot of time looking at the CI, Lean, and Six Sigma job market across the UK/Europe, and the landscape is shifting pretty quickly. I have a full write up you can check out at the bottom, a few things I’m seeing consistently:

1. The 'Green Belt' bottleneck:
   Roles requiring a Green Belt are staying open way longer than average. Companies are desperate for people who can actually *run* a project independently, and basic White/Yellow belt awareness just isn't cutting it for hiring managers anymore.

2. The fastest growing sector isn't manufacturing:
   Financial services seems to be aggressively hunting for Lean Six Sigma practitioners right now.

3. The AI + CI hybrid premium:
   The highest-paying roles are starting to specifically ask for practitioners who know how to integrate AI tools into the DMAIC cycle (especially for data crunching during the Analyse phase).

Has anyone else noticed this shift in their own industries? Would love to hear what you're seeing out there.

PS: I put together a broader write-up on where I see the CI industry heading this year on my site here:

https://www.simplicityhub.co.uk/reports/lss-uk-report-2026.html

I've put together a set of free online calculators that I originally built for my own CI projects and figured they'd be useful to share.

All free to use in your browser — no email required. Currently covers things like:
• Takt Time calculator
• Cycle Time calculator
• OEE (Overall Equipment Effectiveness)
• DPMO & Sigma Level
• Cp & Cpk Process Capability
• Yield & First Pass Yield

Each calculator includes a worked example so you can see exactly how to use it — not just a blank number cruncher.

Full list here: https://www.simplicityhub.co.uk/pages/tools.html

Let me know if there's a calculator you'd find useful that's missing — always taking requests.

Keen to get some opinions on a new build!

Two things here, firstly, I have created a mind map of how to navigate a project at black belt level including all DMAIC stages, tools to use and decision points. For example MSA, checking normality, how to interpret stability and read your run chart, hypothesis testing, when a DOE is useful and how to use it and how to pick and check your control chart etc all can be done without minitab or any expensive software

Secondly, to bolster the mind map I have a built a custom GPT you can feed scruffy notes into and it populates the templates for you, because let’s face it the whole point of lean is removing waste and admin is waste.

Please share your thoughts if you think this is useful and if so would you pay for it?

Already had 2 master black belts say it is very useful but I’d like a more rounded opinion.

I've put together a library of free Lean templates that I originally built for my own CI projects and figured they'd be useful to share.

All free to download as Excel files, Google sheets, Apple numbers — no email required. Currently covers things like:

• SIPOC
• Value Stream Map
• Whys & Fishbone
• Kaizen Event Planner
• Standard Work
• Waste Identification Checklist
• Wastes Assessment

Each template has a worked example and a PDF downloadable how-to guide.

Full list here: https://www.simplicityhub.co.uk/pages/templates.html

Let me know if there's a template you'd find useful that's missing — always taking requests.

Enter your DPMO and instantly see where your process sits on the Six Sigma scale — from 1σ all the way to world-class 6σ performance.