5S organises a workspace in five steps, named in Japanese and conventionally translated to keep the initial: Seiri (sort), Seiton (set in order), Seiso (shine), Seiketsu (standardise), Shitsuke (sustain).
Sort removes what is not needed rather than tidying it. Set in order gives what remains a defined place, positioned by how often it is used. Shine means cleaning treated as inspection — leaks and wear are found this way. Standardise makes the arrangement explicit enough that anyone can reproduce it. Sustain holds it through routine and audit rather than enthusiasm.
It is widely misread as housekeeping. The actual purpose is making abnormality visible: in a workspace where everything has a place, a missing tool or an unexpected item registers in seconds. In a disordered one the same signals are invisible and problems surface late. Several other Lean tools assume you can see deviation quickly, which is why 5S tends to come first.
Most attempts stop after the third S. Sort, set in order and shine produce a visible change and a good photograph; without standardise and sustain the workspace reverts within a quarter, and the failed attempt makes the next one harder to sell.
