Shop Floors Tie the Pokayoke

The following article is a summary of a Times News Network article on March 27, 2004 by Sachin Baxi:

Move over Pokemon, Pokayoke is here. This one’s not for kids – it’s got companies all worked up over “go” – “no go” gauges, alarms, and red flags. They’re not playing games. Pokayoke is serious business because it saves costs, reduces human error, and makes life on the shopfloor easier and more efficient.

Like Pokemon, pokayoke is of Japanese origin. In its simplest form, a pokayoke is a device or piece of equipment that does “mistake proofing”. It does not allow a part to proceed on the assembly line or production line unless the error is removed. Pokayoke also relieves humans of the need for constant vigilance, because it automatically stops any part that may have slipped through, even if the human is tired.

While it’s been around for a few years, Pokayoke has begun to take center stage because the results of these programs are enough to make any cost-conscious CEO sit up and take notice. In M&M’s Mumbai plant, a cross-functional team was formed to implement pokayoke in critical manufacturing functions. M&M reduced its scrap in manufacturing at the plant level by 80%, in rework by 98%, and rework in assembly by 85%.


Most quality management programs are essentially based on the processes used in production and work habits of workers and managers. Pokayoke, though, helps in a hundred little ways by automating the “vigilance” function. Instead of rejecting a faulty part, a pokayoke blows the whistle – literally – as soon as the part moves into the next stage of production. In effect, you catch the “error” before it becomes a part of the finished product.

Tata Motors has introduced more than 4,000 Pokayokes at their Pune facility. A spokesperson stated, “Apart from the reduction in tool breakages, accidents, and rejections, we are more assured of reliability of the process and this increases our confidence in manufacturing consistently good quality products.” It can take simple forms like a “go” – “no go” gauge, which allows parts of only conforming dimensions to be passed, rejecting others. There can be alignment devices that do not allow a vehicle to roll off the line unless the tires are correctly aligned.

A narrow view of pokayoke devices can be as limit switches, that ensure no damage to material at the end of a steel plate, for example. There are also cutouts that break a circuit, much like a fuse or guide pins or laser beams that, if broken, or not aligned, won’t allow a machine to operate. Even office equipment has pokayoke devices – the humble photocopy machine won’t start unless the paper tray is shut or refilled. The pokayoke devices are linked to alarm lights and even visual controls like red flags to halt operation.

Pokayoke, say practitioners, is one element which has contributed significantly to four Indian companies – Mahindra and Mahindra, Rane Brakes, Brakes India, and Sona Koyo – winning the Deming awards last year. The Deming Award, for manufacturing companies, is the holy grail where quality management is concerned. Deming, the American-turned-Japanese quality guru, himself advocated the need to remove constant vigilance in maintenance work from shop floors.