The 5S system is not just for housekeeping but is a problem prevention and identification system. When something is found out of place, the process should be to repeatedly ask "why" until the root cause is discovered. There should be a strong connection between 5S and asking "why 5 times" (5 whys) to fully understand the root problem. A good 5S program builds a culture of self-discipline where standards are followed and small problems can be identified and addressed before becoming bigger issues. Without a 5S system in place, problems would not be visible until they were large or even dangerous situations.

1. Back to basic: 5S without 5W Is Just Housekeeping
(A good 5S program displays a workshop’s culture and mindset and allows problem going to be
solved and prevention.)
The bolt looked common enough, lying there under the conveyor, and the impulse of the group
doing the 5S walk was to throw it into the scrap metal hopper. If it had been a production part it
would lead to stopping shipments until we found the piece that was missing the bolt, but a non-
production part seemed harmless.
However, a 5S system is not a housekeeping program, it is a problem prevention and problem
identification system so, when 5S shows us something out of place, the process should be to
repeatedly ask why until we find the root cause and take action. Taiichi Ohno said that until you
have asked why five times, you probably have not found the root cause. Thus, the 5 Why (aka 5Y)
root cause process is to ask, “Why, why, why, why, why” until you have found the source, or root, of
the problem. Sometimes five times of asking why is not enough, and you have to ask it several more
times.
There should be a very strong connection between 5S and 5 Why. The 5S program (called 5S for the
five parts of the system: Sort, Set in order, Shine, Standardize, and Sustain) is often mistaken as
housekeeping. A good 5S program produces good housekeeping, but it is just an outcome, not the
goal. Five S should be a problem prevention program and a way to identify and fix problems when
they are still very small, thus preventing big problems. As the saying goes: “Take care of the small
things, and the big things will take care of themselves.”
Investigating the Bolt
We began to investigate where the bolt came from and how it had come to rest on the floor. After
speaking to several employees in the area for help, and a couple dead ends, a maintenance
technician was able to identify the bolt as the type used on the conveyor system. We began to look
carefully under and around the conveyor and found that the section of track where we had found
the bolt had only one bolt holding it together, and it was loose. If we had not discovered where the
bolt had come from, the entire conveyor would have fallen apart and shut down production for
hours or days. Even worse, it could have injured someone when it happened.
We also had to answer why the bolt fell out. Conveyor vibration tends to loosen fasteners, so just
replacing and tightening all eight bolts was only a temporary fix while we investigated,
experimented, and developed a fastener system that would not fall out (such as using a lock washer,

2. or locking nut, or thread locking cement, or other method), eliminated the source of the vibration,
improved the preventive maintenance checks, or some combination of these actions that would
ensure this would never happen again. Like all good problem solving, the goal is that the problem
never repeats.
Another example from a different factory was when I noticed an electrical cabinet that was closed
but not latched. It is a violation of basic safety protocol and OSHA regulations but, unfortunately,
not uncommon. The machine was up and running, and the operator was not aware that the cabinet
was unlatched. Asking “why” finally revealed that maintenance had been working on something
during the night but, “Everything must be OK now because we are running parts.” I was assured that
the latch would be secured. Then everything would be neat and clean.
A good housekeeping program will not solve problems and can even defeat problem solving by
cleaning up the evidence needed for root cause analysis and permanent corrective action."
I continued my questioning and discovered that maintenance had been working on the machine
because it was producing nonconforming parts, and they had scrapped many parts until it was shut
down. The maintenance guy that had been working on it had gone off shift and removed his lock
from the lock out/tag out disconnect with the expectation that the day shift maintenance would
finish the work. The day shift operator powered up the machine and began to run parts.
Maintenance was short staffed and assumed that the work was done and was focused on higher
priority machines.
The safety interlocks and error proofing devices had been disabled. Test parts run by midnight shift
had been left on the table and day shift had packed them for shipping. The operator was in danger
of serious injury or death without the safety interlocks and did not even know it. Nonconforming
product could be made at any time and not be caught because the automatic checks were not
working. Known bad parts had already been packed for shipment. Many procedures and protocols
were not followed but a good 5S program should have identified the problem before the operator
restarted that machine.
5S Builds Self Discipline
Lean programs often start with 5S because it builds, and demonstrates, a culture of self-discipline.
Self-discipline is required to follow the standards. This self-discipline forms the basis for further
process improvements such as standard work, kanban and autonomous maintenance.

3. In the first example we could see the bolt on the floor, an out-of-standard condition, because there
were no other parts or trash on the floor. In the second example, a factory with a 5S culture would
not start a machine until it had investigated why the electrical panel was not properly closed.
A program focused on mopping, sweeping and dusting is a housekeeping program. A good
housekeeping program would have put the bolt into the scrap hopper and would have closed the
electrical panel without any other actions. A good housekeeping program will not solve problems
and can even defeat problem solving by cleaning up the evidence needed for root cause analysis and
permanent corrective action.
A good 5S program displays a facility’s culture and mindset and allows problem prevention.
Everything has a place, everything is in its place, and ready for use, and when they are not we start
asking why. This is the beginning of a 5S program that forms the foundation of a lean
transformation.
Without a 5S program in place, we would not have been able to see the little problems until they
had become big, or even fatal, problems.
(This post's Influenced by Robert H. Simonis, Sr. Consultant, KCE Consulting. Apr 14, 2015, I.W.'s). Let
us know if you want a help with Vietnamese version.
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