This post refers to the third S of the series of 5 from the 5S methodology and which stands for Seiso, which can be translated as ‘cleaning’ or for the sake of verbs starting with an S: Shine, Scrub, Sweep, Sanitize and the like.
Once a certain state of cleanliness has been reached, any abnormality should be visible and trigger a corrective action.
A nut or a bolt found on the floor should immediately call for an investigation: is it fallen off the product which is manufactured or from the machine near by? Is it fallen off the tightenings box delivered to the assembly line?
In each of these three cases a missing nut or bolt can lead to a serious problem:
- the product may not be assembled correctly
- the machine may be affected in some way
- the assembly line may be stopped because one part is missing in the precisely counted supplies
Therefore, picking up the nut or bolt and throw it into a trash bin is no good practice. Worse would be simply putting it back to a box holding similar parts on the line.
- Simply disposing parts is not grasping the opportunity to solve potential problems and to improve the situation by solving it
- Putting it back into a box may end up putting it into the wrong box, potentially leading to a later problem
Many people convinced to be knowledgeable about 5S would pick up the stray nut or bolt and get rid of it in any way they consider best and think they did the right thing about 5S.
In fact they help housekeeping, not 5S.
They may pick up stray parts over and over again if nothing is done to understand the origin, cause and designing a robust solution for it not to happen again.
The true 5S spirit would grasp the opportunity to understand where the part came from, why, and how to prevent other parts to fall onto the floor or how to prevent potential later problems.
A seemingly unimportant part as a nut or bolt may be critically important and if missing can lead to a catastrophe.
Until being absolutely certain this is not the case, any discovery of stray material (or document) should be suspected as source of potential major problem and trigger an investigation.