Heijunka
Introduction
Heijunka, the lean method Heijunka, is a central concept in the lean production system that focuses on smoothing and leveling production. Originally developed by Toyota, this method aims to reduce fluctuations in production in order to increase efficiency and minimize waste. This article looks at the Heijunka method, its background, its origins and its relationship to lean production. It also shows how Heijunka can be applied in other areas such as logistics and especially in e-commerce fulfillment.
What is Heijunka?
Heijunka is a method for smoothing and leveling production. In simple terms:
Production is distributed more evenly over time
Instead of producing large quantities of a product at once, smaller quantities of different products are produced alternately
The production sequence and quantity are planned and visualized in advance
This is how Heijunka is used:
Customer demand is analyzed and an optimal production mix is determined
A Heijunka board (a kind of planning board) is created on which the production sequence and quantity are visualized
Production orders are placed on the board as cards, usually for a day or a week in advance
Production then follows exactly this predefined sequence and quantity
The system is regularly reviewed and adjusted if necessary
This method reduces production fluctuations, makes better use of resources and increases flexibility. It helps companies to produce more efficiently and respond more quickly to customer requests.
Background and development of Heijunka
Heijunka is a Japanese word (平準化) that means "leveling" or "smoothing". In the 1950s, Toyota realized that traditional production methods led to inefficient processes characterized by overproduction, high inventory levels and uneven workloads. To address these challenges, Toyota developed the Toyota Production System (TPS), in which Heijunka plays a key role.
The aim of Heijunka is to manage production in such a way that it meets customer demand without creating unnecessary overloads or idle times. By leveling production, companies can achieve an even workload and make optimal use of resources. This leads to smoothed production, which minimizes fluctuations and ensures balanced production.
Relationship between Heijunka and Lean Production
Lean production strives to eliminate waste and create value for the customer. Heijunka is one method within this approach as it helps to reduce the seven types of waste:
Overproduction
Waiting times
Transportation
Revision
Stocks
Movement
Defective products
By leveling production, companies can build a more stable and efficient production chain that enables them to respond quickly to customer needs while saving resources. The Heijunka principle reduces fluctuations in production processes and enables extensive harmonization of workflows throughout the company.
The Heijunka method in detail
Heijunka aims to level both the production volume and the product mix in order to achieve leveled production. There are two main aspects:
Volume leveling: Production is planned in such a way that a constant quantity is produced daily or weekly, regardless of short-term fluctuations in customer demand. This reduces the number of necessary adjustments to the production plan.
Product mix leveling: Different product types are produced in small batches and at regular intervals to meet different customer requirements. This reduces the number of products that need to be kept in stock and reduces the number of tools and changeovers.
The implementation of Heijunka requires detailed forecasts of customer demand and the flexibility to adapt the production plan accordingly. By visualizing the current actions and the individual process steps using the Heijunka board, employees can easily understand the production plan and react to deviations. The Heijunka board is the ideal tool for visualizing and controlling production.
Implementation steps of Heijunka
Analysis of customer demand: understanding long-term demand in order to determine appropriate production volumes.
Creation of a production plan: Develop a plan that levels both volume and product mix.
Use of Heijunka boards: Use of visual tools to support production planning and control.
Continuous improvement: Regular review and adjustment of the plan based on feedback and changing conditions.
What is a Heijunka Board and how can it be used in practice?
A Heijunka board is an important tool for production smoothing and leveling in lean management. It is used to plan and visualize production in order to achieve an even production flow.
Here are the most important points for using a Heijunka board:
Structure and function of the Heijunka board
The board is typically structured as a matrix, with time intervals (e.g. hours or days) on one axis and product types on the other.
Production orders are placed on the board as cards to show the planned production mix and scope.
It enables a visual representation of the leveled production over a defined period of time, usually a week or a day.
Application of the Heijunka Board in practice
Production planners can enter the demand for the planning period and have the board automatically leveled. Production employees can see at a glance which products are to be produced in which order and in what quantity. It helps to balance out work peaks and achieve even capacity utilization. Delays and deviations from the plan are immediately visible.
Advantages of Heijunka
Reduces fluctuations in production and creates a stable workflow.
Enables just-in-time production and delivery.
Minimizes stock levels and overproduction.
Facilitates synchronization with suppliers.
Application of Heijunka in logistics
The use of Heijunka can also increase efficiency in logistics. By leveling incoming and outgoing goods, balanced production can be achieved. This reduces bottlenecks and waiting times, regardless of the company in question.
Transport planning: leveling of deliveries to ensure even utilization of vehicles and personnel. The implementation of Heijunka reduces overloads and improves delivery times.
Warehouse management: Smoothing of incoming and outgoing goods to avoid overloads and optimize stock levels. The number of tools and individual parts required can thus be better managed.
Inventory management: Reduction of fluctuations in inventory management through consistent replenishment processes. This requires extensive harmonization of processes and clear communication between employees.
Application in e-commerce fulfillment
Although Heijunka is primarily used in the manufacturing industry, the concept can also be transferred to retail and e-commerce:
Order processing: leveling of the daily order quantity for even utilization of the shipping process.
Stock replenishment: planning of regular, smaller reorders instead of large, irregular deliveries.
Staff planning: more even distribution of the workload in customer service or the warehouse.
Offer planning: Balanced distribution of special promotions and product launches throughout the year.
Returns management: leveling of returns processing to avoid work peaks.
By applying Heijunka principles, retailers and e-commerce companies can also streamline their processes, use resources more efficiently and react more flexibly to fluctuations in demand.
In e-commerce, companies are often confronted with unpredictable fluctuations in demand, e.g. due to promotions or seasonal peaks. The implementation of Heijunka can help to meet the requirements of companies in the digital market.
Workload distribution: planning of order processing to avoid peaks and deploy personnel efficiently. The technical staff and can be supported by training in Heijunka.
Process optimization: Standardization of packaging and shipping processes for different product types. Approaches can be adapted in companies to achieve a balanced factory.
Stock replenishment: leveling of replenishment processes to avoid out-of-stock situations. Taking customer A and their orders into account can help to plan production better.
Virtual tools: The use of VIRTUAL REALITY and tools from our VR catalog can help to visualize and optimize processes.
Practical application and implementation of Heijunka
Step-by-step instructions:
Data collection and detailed forecasting: Collect historical data on customer demand to identify patterns and trends. This can be one-off data on the processing of past orders and inquiries.
Demand forecast: Use the data to forecast future demand. Also take into account current promotions and customer requests, such as customer remodeling requests.
Production capacity analysis: Determine the maximum production capacity and identify bottlenecks in the clocking process and the individual process steps. A creative process can help to find solutions to identified problems.
Creation of a Heijunka plan: Develop a plan that levels the production volume and product mix over a certain period of time. It is important to correctly determine the number of cards in the Heijunka box in order to control the number of products and the individual parts required.
Visualization with the Heijunka board: Implement the board as a visual management tool. The cards placed in the box represent the orders to be produced and help to control the production plan and ensure production at the right time.
Implementation of pull systems: Use Kanban systems to control production based on actual demand. This reduces the number of intermediate stocks required and helps to level production.
Continuous improvement process: Monitor production and adjust the plan if necessary. The continuous improvement process is a creative process that helps to optimize production.
Conclusion
Heijunka is a powerful lean method that enables smoothed and balanced production by leveling production processes and demand. This leads to an extensive harmonization of processes throughout the company and reduces waste. Through the creative process of implementation and the continuous improvement process, companies can become more efficient and competitive.
The use of Heijunka reduces fluctuations in production and improves the controllability of production. Technical employees and store floor management play an important role in this by recognizing management deviations at an early stage and adapting processes. The active involvement of employees and the use of technologies such as VIRTUAL REALITY can support the implementation of the Heijunka lean method.
Further steps:
Analyze your current processes for fluctuations and identify areas where Heijunka can be applied.
Develop an implementation plan involving relevant stakeholders, including customer A and customer conversion requests.
Train your employees in lean principles.
Rely on a creative process and a continuous improvement process to constantly optimize smoothed production.
Through integrative application, your company can not only improve its production processes, but also become more competitive in the long term and increase customer satisfaction. A balanced factory and an efficient overall factory are key goals that can be achieved.
Further lean tools:
Deep-Dive: Lean Management Guide