Lean manufacturing has been adopted by countless production operations around the world over the last several decades, and for good reason. Principles that increase the efficiency of your workplace and create a smoother flow in production can only be beneficial for your workplace. I’m here to introduce to you the epitome of flow and efficiency of sequence, Heijunka. Simplified, Heijunka is the concept of a one-piece-flow that allows production to be increased by taking a line that produces one product and making in flexible enough to produce several others. Just how many variants are created on one line changes from industry to industry, but the basic principle stays the same.
Look at it this way:
Let’s say you’ve got four assembly lines producing four different types of widgets in your factory. One day, demand for one of the widgets plummets and you receive very few orders. At the same time, demand rises slightly for each of the other varieties but those assembly lines are already producing at maximum capacity and you begin to lose out on business from customers whose orders you cannot accommodate in a timely manner. “But wait, I’ve got another assembly line,” you think to yourself. But alas, that assembly line is highly specialized in making the type of widget that is no longer in demand, and as such its workers and machinery sit idle and inefficient. Your only option becomes to re-tool that assembly line to produce another type of widget that is still in demand, but changeover can be costly and time consuming when you don’t have many interchangeable parts, as is the case with highly specialized machinery. Worse yet, what if demand shifts while you’re still changing over your assembly line and the old widget is back in demand? That can turn into a real mess, and quickly!
Whats the Point?
The point of Heijunka, and having assembly lines easily adaptable for multiple purposes, is to avoid possible hangups in efficiency like the ones described above. Heijunka allows your production to more easily mirror customer demand without down time. Production quickly becomes balanced across all of your available means (machinery and staff, mainly) instead of focused in different areas that must work rigidly and independently of each other.
Mixing multiple products within a line seems counter-intuitive to many when thinking about keeping things simple and flowing smoothly. One of the main reasons behind this is that tasks can be broken down into small units that help create multiple products. Let’s say you’re producing two models of cars. On the outside, these cars are very different and no one would ever guess they were made in the exact same place. On the inside, however, certain parts, like the metal bumper base, the door frames, and the wheel wells, are identical. These parts are all simple building blocks of your finished products that can be made at the same time and yet created for multiple purposes, that’s efficient, and that’s Heijunka.
All that’s really left is for you to start to think about how Heijunka can fit into the niche you fall under. How can you eliminate redundant steps by consolidating certain process to one line? How about creating two different products altogether in the exact same space by making it easier for workers to swap tasks depending on demand? The sky is the limit for thinking here, so get creative!
- Heijunka Box
- Improving Workplace Efficiency: One Lean Step at a Time
- Changeover: Streamlining Your Business
- Chaku Chaku & Other Lean Terms You Should Know
- Shojinka: The Secret Ingredient of Highly Effective Production
- Increasing Warehouse Productivity