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How to find Abnormalities and not Problems in a lean factory

Updated: Sep 13, 2023


A car parked by traffic lights on a hill

Real life examples of lean thinking


The picture at head this blog is a great way to explain Change Points (Henkaten) - an important lean principle - through real life. People serious about understanding lean and kaizen tend to embrace the world around them, by mining for examples. We've put out blogs ourselves about discovering kaizen examples in elite pro sports and improving flow, by reducing delays, in a department store cafe.


Change Points (Henkaten) and traffic lights


The picture shows the traffic lights at the bottom of the long raking downhill drive into the market town of Ashbourne in Derbyshire (where I currently live). On this day, I was walking back up the hill and noted something of interest. If you look closely at the middle left of the picture, a car is parked up on the kerb. Squint a little harder and you'll note that the sign on the back of the car says "Traffic Signal Maintenance".


This I noted because it represents a potential change point and those who run strong lean businesses love Change Point Management (even though they may not use that exact terminology). In tandem, they embrace the time-travelling benefits of the mantra "find abnormalities NOT problems"


What are Change Points in manufacturing?


Change points were a Eureka moment for us at Sempai. Think about this statement:


Most defects and accidents happen after something has changed


If you had the same...

  • trained people (Man/Woman) turning up every day

  • with good quality parts (Material) that arrived on time

  • manufacturing with the right machines/tools that didn't break (Machine)

  • following strong Standardised Work (Method)

  • with the right lighting and temperature (Environment)

...you'd have less problems that you do currently, right?


Example Change Points (5M1E) with examples


Man/Woman (People)

changes to people working in the area that might affect how well things run

e.g absenteeism or holiday


Machine

changes to machines, jigs and fixtures that might affect how well things run

e.g a change to settings of a machine tool


Method

changes to the way the machine operates or the Standardised Work of the operator

e.g process conditions altered during the outgoing shift


Material

changes to the parts or components (materials) used to make the products you sell

e.g trialling new material with a current supplier


Measuring Equipment

changes to the gauges used for quality assuring the products you sell

e.g torque wrenches going to, or returning from calibration


Environment

changes to the conditions you make your products in

e.g it's a hot or cold day – known variability caused by temperature changes


Find Abnormalities NOT Problems!


The key lies in recognising that many defects and accidents happen after something changes. As I knew I would be driving down the hill later, several thoughts occurred to me;


1) This is a potential abnormality as there's no guarantee that the lights will behave exactly as before


2) Is it routine maintenance OR a change to the sequence OR a change to the timing?


3) Either way, the lights might operate differently OR the confirmation that they work as intended after the maintenance may be flawed.


When I approached the lights later that day it was with a heightened sense of awareness for my own driving with an eye on the potential confusion of others. This is the strong operational practice of spotting & reacting to abnormalities (traffic signal car parked) rather than sorting the subsequent problem (accident).


We summarise this approach in our award winning digital lean toolkit SempaiGuide with an example from a pub/bar:


a screen shot from SempaiGuide

another screen shot from SempaiGuide

Spotting the bottle leaning against the glass, and standing it back up, is a lot easier than clearing up smashed glass and sticky sugary mixer.


Lean Manufacturing Examples


Factory examples? take your pick... new operator on line, new supplier for an existing part, change to the way a machine operates, kaizen changing the work sequence on an upstream process etc. If we brief these out to our people on the shop floor in advance, they are forewarned and we can manage around the Change Point.


The great thing about living the 'Change Point' life is that it holds your feet to the fire to define normal (Standardisation) so that abnormal becomes very obvious. It also draws supporting functions like engineering and materials into closer communication with Team Leaders on the gemba. What's not to like about that?


If you'd like to know more about training your Shopfloor Leaders to see problems before they occur, take a look at our courses and coaching.


Thanks

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