5S is the name of a workplace organization method that uses a list of five Japanesewords: seiri, seiton, seiso, seiketsu, and shitsuke. Transliterated into Roman Script, they all start with the letter "S".^[1] The list describes how to organize a work space for efficiency and effectiveness by identifying and storing the items used, maintaining the area and items, and sustaining the new order.^[2]The decision-making process usually comes from a dialogue about standardization, which builds understanding among employees of how they should do the work.

In some quarters, 5S has become 6S, the sixth element being safety.^[3]

Other than a specific stand-alone methodology, 5S is frequently viewed as an element of a broader construct known as visual control,^[4] visual workplace,^[5] or visual factory.^[6][7] Under those (and similar) terminologies, Western companies were applying underlying concepts of 5S before publication, in English, of the formal 5S methodology. For example, a workplace-organization photo from Tennant Company (a Minneapolis-based manufacturer) quite similar to the one accompanying this article appeared in a manufacturing-management book in 1986.^[8]