The third S of the series of 5 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.
In the introduction post to this series, I summarized 5S as a philosophy, approach or methodology to provide simple, effective rules for tidiness, maintaining workplace in good, safe condition and fostering a continuous improvement of the standards, rules and discipline.
Good quality as well as safety is easier to ensure in a clean and tidy place. But cleanliness is not only for the good aspect of the place, it is also a helpful to notice damages on machines and equipment such as leaks, breakage and misalignments.
These minor damages, if left unattended, could lead to equipment failure and loss of production and/or quality issues. Regular cleaning is a type of inspection. Seiso is an important part of basic TPM; Total Productive Maintenance
Daily cleaning is an opportunity to assess machines’ condition and to detect the forerunning signs of potential trouble. While sweeping a machine, an operator may notice abnormal heat or uncommon smell, vibrations, leaks or hear unknown sound.
Some early warning signs may remain unnoticed if covered with grease, lubricant or scrap.
In a clean, tidy environment, any abnormal condition is noticed much easier and faster. Again, a leak of lubricant would be noticed immediately on a clean machine, while it would not if the machine was constantly oily.
In the example of this picture, the lubricant was not that easy to see (at least from some distance) on the green paint, I therefore took a white wipe to make it visible.
Fallen-off nuts and bolts from equipment or product get noticed in a clean environment, not in a dirty one.
A clean workplace is also important to quality. I remember my early years as production manager of the French Yamaha Hi-Fi plant, and the care we took to prevent the front face from our high-end CD players or Receiver to get any scratch.
Cleanliness of the workplace, the jigs and even sweeping cloths was crucial to prevent the sensitive surface to be scratched. Would the apparatus later be rejected on inspection for front panel scratch, it had to go through a long costly exchange process.
Seiso is often mistaken as plain cleaning, but there is more about it. Once the machine or the workplace has been cleaned up to a satisfactory, nominal state, the next objective is to work on preventing it to get dirty or degraded again. It is smarter to avoid the need of cleaning / repair than to clean / repair over and over again!
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Related: Just posted: Why 5s’s Scrub & Shine is not (only) about cleaning