Complementary tools to reduce impact of stopping the line (Jidoka)

What is Jidoka?

Jidoka is one of the main pillars of Quality Built In. It’s also one of the most thorough ways to find and fix quality errors. This is because of its two core ideas.

1. Autonomation: Machines are allowed to run autonomously and are equipped to recognize errors as soon as possible. When they detect an error, they completely stop and alert an operator so that the error can be fixed quickly. Other names for this are “automation with human touch” and “automation with human intelligence.”
2. Everyone is empowered to stop the line if they see an error. Whether you use Jidoka already or not, everyone on the line is supposed to be ensuring quality. However, this doesn’t always happen. Then mistakes result in rework, scrap, and, even worse, unhappy customers.

It may seem extreme or even dangerous to give everyone the power to stop the line. That’s where the idea for this post came from. The thought of so-and-so stopping the line whenever they want to doesn’t have to keep you up at night. You can reduce the stress of stopping the line.

• Reduce the need for Jidoka (and stopping the line) by anticipating quality errors and managing the line to prevent human or machine error. There are very complementary tools to prevent quality errors, some are implemented before the line even starts running. We’ll discuss a few tools below.
• Prepare your teams to respond as quickly, effectively, and efficiently as possible. It’s easier to imagine stopping the line when your team will act more like a pit crew and less like kindergarteners tripping over a collapsed tower of blocks. Absolutely everyone in a pit crew has a job and there’s no hesitation to do it when the time comes. This doesn’t happen by chance.
• Ask yourself why you’re so afraid of stopping the line to fix quality issues as soon as they arise. Isn’t it ideal to send the customer a perfect product? Of course it is. What is holding you back? If it can be resolved, resolve it. If it seems like it can’t be resolved, then you’ll need to decide how to cope with it.
• Remember the accountability of stopping the line. It’s not like someone can stop the line without being noticed. In fact, that’s part of the point. The goal of Jidoka is to draw immediate attention to the error so it can be corrected and the line can return to producing quality products. If you have a team member who would stop the line and run away as a joke or to dodge responsibility, that’s a different issue.

All of this being said, we realize some lines are harder to stop than others. There are situations where simply stopping the line to fix an error isn’t so simple. If this is your situation, the ideas above can still be applied. It’s always best to anticipate and prevent errors, prepare your teams to respond appropriately, and to understand all the risks that are facing your operation.

How can we reduce the need for Jidoka?

The following three tools are some top choices for preparing your operation for utilizing Jidoka.

Heijunka assists with and reduces the need for Jidoka by limiting the batch size of each product. When a plant is running according to Heijunka, the production schedule is aligned with the customer orders rather than batch production where large stores of products are created based on expected customer orders. Smaller batches mean more frequent adjustments and opportunities to make corrections. In order for this to work properly, it will also be necessary to train your teams on the transitions they’ll need to make between batches. It may also require redesigning the work cells to facilitate smooth and correct transitions.

Failure Mode Effect Analysis (FMEA) helps identify potential errors, their effect on production and the likelihood they’ll be found. It requires the organization to look at how they’d know if the error was going to happen and how they’d respond. Translation: the solution is known before the problem occurs and either the problem can be resolved before the line starts to run or the solution can be shared with the relevant teams before the problem occurs in active production.

Andon draws immediate attention to any problem that is discovered, such as a light the operator turns on when something goes wrong. For it to work most effectively, the teams are trained on what exactly to do when the Andon signal goes on. Otherwise, it’s almost pointless.

There are many other tools you could use to take the edge off the stress of stopping the line. This is just a start. Anything that helps your team foresee errors or prepare for how to deal with them will help you respond to and recover from a Jidoka action quickly. In the midst of those preparations you’ll likely accomplish other things like documenting missing steps in a process, discovering a new skill a co-worker has, or learning about the work styles and preferences of the team.

One of the biggest benefits of Jidoka is giving your team members the confidence to speak up when they need help or see an error. In the Lean methodology, the voice of the person actually performing the work is critically important. The more you can foster that confidence and encourage the culture of teamwork, personal power, and universal accountability for quality, the more successful your Lean efforts will be.