At Toyota, Heijunka is the mantra or technique that has been instrumental in leveling or smoothing production for years. This Japanese concept empowers manufacturers to level the production type and quantity in a way that meets customer demand while lowering waste and improving efficiency.
Put simply, Heijunka drives lean manufacturing all along the value stream by controlling capital expenses, inventories, lead time, and labor. Instead of manufacturing items in batches, with Heijunka, it is possible to achieve high-quality Just-In-Time or JIT production.
This article dives deep into the idea behind Heijunka as well as its benefits, implementation, and more.
What is Heijunka? The Problem It Solves in Manufacturing
Mass production of anything usually leads to inconsistent quality and productivity as well as the excess burdening of manpower and machines. And together, these pitfalls translate to unnecessary waste. This is what Heijunka tackles by fostering the ideal relationship among:
- Stability (averaging the long-term production type and volume)
- Predictability (smoothing demand)
- Flexibility (lowering the time for changeover, i.e. when a machine stops churning out one product and transitions to producing another)
These examples illustrate how Heijunka augments manufacturing efficiency:
By-Quantity Leveling
Say, every week, you get an order of 500 shirts, but there is a day-by-day variation. From Monday to Friday, the order involves 200, 100, 50, 100, and 50 items. Hence, for lean production leveling, you set a small number of finished shirts aside, ready for shipping, to meet Monday’s high demand.
And throughout the week, you decide on producing 100 pieces every day. As a manufacturer, this helps you use assets more efficiently along the value stream while also meeting customer needs.
By-Type Leveling
Say, you manufacture hats in four different models, A to D. And every week, the demand looks like this – 5As, 3Bs, 2Cs, and 2Ds. You might follow this sequence if you are a batch producer focused on economies of scale – A A A A A B B B C C D D.
However, with Heijunka, you can adopt a leaner process and avoid sending suppliers big infrequent batches. Thus, your sequence will probably look like – A A B C D A A B C D A B. You will also end up minimizing changeover time and enhancing the production system.
Key Benefits of Heijunka for Manufacturers
As a lean technique, Heijunka doesn’t just match supply with real demand, but also enables a smooth, continuous flow of work. It establishes an optimal pace of production, makes operations more stable, and allows manufacturers to align better with demand fluctuations. Let’s look closely at the key perks:
Reduced Inventory and Waste
Since Heijunka ensures your production is in close alignment with demand, you can reduce the number of goods that are being processed or finished in the inventory. The technique helps slash the possibility of damaged inventory and waste from excess production as well. Moreover, a lower level of inventory means more room for storage and better cash flow.
Better Stability and Workflow
By spreading the workload across various processes, Heijunka helps in minimizing bottlenecks, disruptions, and defects. Hence, workflow as well as operational continuity improves. The manufacturing of diverse items is also better sequenced and scheduled. Also, setting the production pace ensures the overall system is more stable and the workflows predictable.
Improved Predictability and Adaptability
Heijunka simplifies and smartens the act of sequencing and planning production. Hence, you can dynamically adapt to demand-related changes or a different product mix easily. Whether demand dips or shoots up, your production system can adapt fast without exerting excessive burden on existing capacities.
The workflow will be more standardized and disciplined, which implies minimal lead time variability. Hence, you can easily predict the effectiveness of meeting customer demands in the future.
How to Implement Heijunka: 7 Steps for Your Shop Floor
Implementing Heijunka for lean management of the shop floor requires you to adopt these key steps:
Group Products
To manufacture different kinds of items with minimal loss, group products based on parameters that are similar. This will reduce the time and effort that goes into prepping a machine for changeovers. Hence, you can quickly align supply in line with fluctuating demand.
Assess Takt Time
Takt time helps you assess the speed of product manufacturing that will satisfy demand. And estimating it beforehand will help in establishing a suitable production speed.
Put Together a Production Schedule
Craft a leveled schedule taking the takt time into account. It should clarify the production sequence of various product groups, so the workflow is smooth and seamless.
Leverage a Heijunka Box
This box represents the pattern of sequencing mentioned above in a visual manner. Based on the schedule, the box is loaded with Kanban signals or production cards. Hence, scheduling production, streamlining changeovers, and tweaking the production sequence based on demand becomes convenient. Hence, the Heijunka box:
- Resembles a grid that displays product types and production amounts of each
- Visualizes the orders for each product, based on its average demand
- Levels the sequence of manufacturing to optimize workflow
Manage Change
If workers are familiar with batch production, you might need to explain the advantages of Heijunka in detail for easy transition. Besides effective communication, providing training can help with this too.
Monitor Constantly
Monitor Heijunka boxes as well as production workflows regularly, so you can spot any deviations quickly. And take corrective actions at the earliest. Make sure managers go for Gemba walks on a daily basis to detect and address problems in real time as well.
Optimize Shop Floor Layout
This is an integral part of lean manufacturing since the product mix and takt time are likely to change over time. Through standardization and prompt bottleneck detection, you can ensure that data and materials flow smoothly.
How Heijunka Fits Into Continuous Improvement
Heijunka isn’t just a one-time solution for a consistent, balanced, predictable, and efficient production ecosystem. It helps you create, track, assess, and refine production schedules continuously in line with demand-related variations.
The technique allows you to review production schedules, identify gaps, and make corrections regularly. Hence, in manufacturing, Heijunka is essential for achieving resilience in a dynamic landscape. You can constantly streamline workflows, operational efficiencies, waste management, flexibility, and cost control.
Why Now Is the Time to Level Production
The manufacturing landscape is highly competitive and dynamic, which calls for a stable, predictable, and flexible production system. Hence, traditional batch or mass production is gradually losing out to Heijunka-led leveled production.
By embracing Heijunka, you can deal with demand fluctuations efficiently while streamlining workflows, lowering costs, and reducing waste and inventory. In the process, you also enhance product quality and create a culture of constant improvement.
Most importantly, implementing, assessing, and refining the Heijunka technique to attain lean management is a breeze with fabriq. Through digitalization, you can make workflows smoother, boost communication, track crucial metrics, gather valuable insights, fix problems, and keep improving. fabriq’s tools enhance visibility, agility, accountability, and analysis in a customized manner.
Explore Heijunka with fabriq and transform how you level production, eliminate waste, and improve efficiency.
