The first S stands for Seiri or Sorting, which means keep only the necessary items within work area, and dispose or keep in a distant storage area the less frequently used items. Unneeded items may be returned to for sharing with others, e.g. tools no longer required or even discarded. Eliminate old broken tools, obsolete jigs and fixtures, scrap and excess raw material.
Seiri fights the habit to keep things because they may be of some use someday, which seldom happens. Seiri helps to keep work area tidy, improves finding and fetching and efficiency at large.
Sorting makes work easier and more efficient by eliminating hindrances and disturbances. Clutter can lead to lengthy searches and ultimately forgetting something because of the distraction caused by unnecessary items.
Sorting generally clears much space and is therefore an excellent way to gain valuable floor space.