5S (methodology) - The Evolution of 5S

The Evolution of 5S

Many Western companies now promote Hirano's approach with a sixth 'S' added for Quality. Not unnaturally, there is some debate over this, with devotees on both sides of the argument. The sixth S serves a fundamental purpose – it reminds everyone of the need for Quality. A key lesson taught by Japanese automobile manufacturers, and one central to the Toyota Production System, is that traditional levels of performance must be not only exceeded, but replaced by a completely different perception of the scale of what is acceptable. Rather than managing defects in percentage terms, Western managers heard of management in 'parts per millions', with single-figure levels of defects being the goal. Given that a 1% failure rate equates to 10,000 ppm the scale of improvement to be sought as part of the adoption of Lean was, to say the least, spectacular.

This improvement in quality levels could, of course, only be achieved with a complete re-definition of processes and culture within Western manufacturing. This includes issues such as 'Design for Manufacturing' and the fundamental change from Quality Control to Quality Assurance (that is, the Quality department role moving from inspecting and highlighting problems to guaranteeing methods and procedures to eliminate errors). Housekeeping, of course, is central to this and adding a sixth 'S' highlights this.

The contrasting view, and the one taken by Hirano in establishing this approach, is that each and every 'S' is a phase. As noted earlier, a major lesson for Westerners was Hirano's 5S methodology breaking the program down into a series of steps. The sixth 'S' does not add to this; Quality is not a phase, it is an objective – along with productivity and the others described above. Moreover, it is an objective of each and every phase. Adding the sixth 'S' might be perceived as recommending a program carrying out the sorting out, organising, cleanliness, procedural and cultural steps and subsequently building in Quality, which of course is not possible. If all the objectives have not been built in throughout each element of the definition of the new way of working then they can not be applied as an additional phase.