Operation: “Shitsuke” operations for maintaining “Seiketsu” in an assembly workshop.
Problem: This is the second year since 5S activities have been introduced into the workshop. The 5S philosophy has become entrenched and accomplishments have been made. There are still, however, defects and frequent stoppages. The results of an investigation show that there is still generation of a large amount of dirt, trash, and dust during operations which covers the entire workshop. When workers come in the morning they find a layer of dust on the machinery, work tables, racks, materials, and parts which they cleaned the evening before. This is a minor defect which builds up until defects and frequent stoppages are caused. If things progress in this manner, 5S will be no more than an empty motto and major defects and breakdown are bound to occur.
It was decided that this problem should be taken up immediately, and all workers were called to help solve it.
Grasping the Situation in which “Shitsuke” has not become entrenched and Minor Defects occur:
First of all, workers decided to divide the work of investigating the sources of dirt, trash, and dust generation and the paths by which they enter the workplace, the losses that were being incurred because of defects and breakdowns and what the causes were.
Obvious problem: 4 ‘S’ are being enacted only for places which can be seen
After searching for the sources of dirt, trash, and dust, and following their paths, the following was discovered.
(1) Uptil now, “Seiso” and “Seiketsu” have been centered around machinery, jigs, tools, moulds, and materials with “Seiso” and “Seiketsu” done for the places that stood out. The parts of those items which cannot be seen are still covered with years of dirt, trash and dust.
(2) Floors aisles, walls, ceilings, windows, exits and entrances, racks and areas around buildings are also covered with dirt, trash and dust.
(3) Work clothes, aprons and safety shoes are also dirty are the cause of other things getting dirty.
(4) A clean situation is supposed to gradually spread out, but it has stopped within the limits.
Estimated losses: Decrease in added value figure due to reduction of production and fear of added cost due to accidents and breakdown repairs
(1) When a defect occurs, losses include not only defect cost, but also a decrease in added value figure because production is also reduced.
(2) When a breakdown occurs, losses include not only defect costs, but also a decrease in added value figure because production is also reduced.
(3) Other losses included waste due to energy costs and accident costs.
Estimating the total of all these losses produced a large monetary figure. All of the workers decided that they must decide what was needed to be done in order to stop the losses, make repeated improvements, and make the new methods into customs, and in so doing, reap a profit of the size of their bonus. In order to decide what ought to be done (improvements), they decided to grasp the harmful factors.
Harmful factors: Partial “Seiso” and lack of “Shitsuke” and measures to prevent generation of dirt
This is described as follows:
(1) Aisles are dirty, so conveyance cars carry dirt, trash, and dust into the workshop.
(2) There is insufficient “Seiso” of wheels of small conveyance cars.
(3) “Seiso” and “Seiketsu” maintenance of floors and aisles have not spread out to the entire company yet. Some workshops do them and others do not. The dirt, trash, and dust on floors from workshops, which don’t do cleaning ends up in the workshops which do clean, and this destroy their desire to continue efforts.
(4) The duties of each workshop have not been divided properly. Walls, windows, and racks which do not belong to any particular workshop have not been assigned to anyone to do, and they are a source of the problem.
(5) Cleaning equipment is not stored close at hand so that cleaning can be done quickly and easily when it is needed.