Heijunka: The Definitive Guide to Production Leveling and Lean Efficiency

In today’s volatile market, manufacturers face constant pressure to meet fluctuating customer demand while minimizing costs and maximizing efficiency. Running production in large, infrequent batches might seem straightforward, but it often leads to a cascade of problems: excessive inventory, overburdened resources, long lead times, and the inability to quickly adapt to market changes. This is where the Lean principle of Heijunka comes into play: a powerful methodology from the Toyota Production System (TPS) designed to bring stability, predictability, and efficiency to your operations through production leveling.

This comprehensive guide will delve into the concept of Heijunka, exploring its definition, origins, core principles, implementation tools like the Heijunka board, benefits, challenges, and its crucial role within the broader Lean framework. Whether you are new to Lean or looking to optimize existing processes, understanding the Lean principles of Heijunka is essential for achieving true operational excellence.

Beyond Batches – Why Stable Production Matters

Imagine a typical manufacturing scenario without production leveling. On Monday, a surge of orders arrives, forcing the plant to work at full speed, potentially requiring overtime and overburdening equipment. By Wednesday, demand drops, leaving workers idle and machines underutilized. Friday brings another peak, a smaller one, requiring a quick and inefficient changeover. This roller coaster of activity is known as Mura, or unevenness/variation.

The Chaos of Uneven Production (Mura)

Mura creates significant problems:

• Increased Stress (Muri): Leads to overburden (Muri) on both people and machines during peak times, increasing the risk of errors, defects, and breakdowns.
• Generation of Waste (Muda): Inevitably results in various forms of Muda (waste), including:
  • Overproduction: Making more than needed during peaks “just in case.”
  • Excess Inventory: Holding large stocks to buffer fluctuations.
  • Waiting: Downtime during pauses.
  • Inefficient Transport and Motion: Moving large batches infrequently.
  • Poor Responsiveness: Difficulty adapting to changes in customer orders or product mix.
  • Hidden Problems: Large batches can hide quality issues until significant quantities of defective products have been made.
  • Overburdening Suppliers: Transmitting irregular demand upstream creates instability throughout the supply chain (the “bullwhip effect”).

Introducing Heijunka: The Lean Solution for Stability

Heijunka (pronounced “hei-yun-ka”) offers a strategic alternative. It is the Japanese term for “leveling” or “smoothing,” also known as production leveling or customer order leveling (Boutbagha and El Abbadi, 2023).

Instead of reacting sharply to the peaks and valleys of customer orders, Heijunka aims to create a constant, predictable production rhythm over a defined period. It involves averaging the production volume and often mixing different product types within that leveled schedule. Importantly, Heijunka is a production leveling tool used to support Just-in-Time (JIT) and Kanban systems (Phatale, 2020).

What You Will Learn in This Guide

This guide will provide you with a deep understanding of what Heijunka is and how to leverage it:

• Core Definition: Understand the definition of Heijunka and its place within the Toyota Production System.
• Leveling Techniques: Understand leveling by volume and by product type/mix.
• Key Tools: Learn about the Heijunka box (or Heijunka board) and its role alongside Kanban.
• Implementation: Discover the steps involved in Heijunka scheduling and its implementation.
• Benefits and Challenges: Weigh the significant advantages against the potential obstacles.
• Context: See how Heijunka relates to JIT, Lean, and Six Sigma.

What is Heijunka? Demystifying the Definition and Core Concept

While often simply translated as “leveling,” the concept of Heijunka encompasses more than just smoothing numbers. It is a fundamental element of Lean manufacturing for production leveling and variability reduction (Gomma, 2025), aimed at creating stability and predictability as a prerequisite for efficiency and flow.

Heijunka Definition: More Than Just “Leveling”

Heijunka is a Lean method for reducing unevenness (Mura) in the production process by leveling the volume and mix of items produced over a specific period. Its goal is to establish a constant, repeatable work pattern, which in turn minimizes overburden (Muri) and eliminates waste (Muda).

According to Boutbagha and Abbadi (2023), Heijunka is a central concept of the Toyota Production System (TPS) that seeks to maintain the flexibility and stability of the production system by producing the same quantity of products at defined time intervals. Similarly, Rewers and Diakun (2021) state that Heijunka is considered a modern method of production planning and control, aiming to find a balance between order fluctuations and the stability of the production flow.

Instead of producing large batches of a single product based on short-term fluctuating orders, Heijunka averages demand over a longer period and creates a schedule that produces smaller quantities in a repetitive sequence, often mixing different product types.

Origins: Heijunka in the Toyota Production System (TPS)

Heijunka is a cornerstone of the Toyota Production System (TPS) (Soliman, 2022), alongside concepts like Just-In-Time (JIT) and Jidoka (autonomation). Toyota realized that reacting directly to fluctuating customer orders created massive inefficiencies. By leveling production, they could:

• Stabilize work for employees.
• Drastically reduce inventory requirements.
• Make the production flow more predictable.
• Establish consistent demands on suppliers.
• Enable the effective implementation of JIT.

Without Production leveling, constant variation would make it impossible to maintain a true JIT system, which relies on a smooth flow.

The Meaning of Heijunka in Manufacturing: Smoothing the Flow

In essence, the meaning of Heijunka in manufacturing is to transform erratic external demand into a stable internal production rhythm. It acts as a buffer, protecting the production system and the upstream supply chain from volatility. This enables standardized work, simpler management, and the systematic elimination of waste.

According to Korytkowski et al. (2013), smoothed production seeks to balance both production volume and product mix, improving production efficiency. It helps bring stability to the manufacturing process, converting uneven customer demand into a smooth and predictable manufacturing process.

The Fundamental Goal: Eliminate Mura (Unevenness) to Reduce Muri (Overburden) and Muda (Waste)

The “3Ms” – Mura, Muri, Muda – are central to Lean thinking.

• Mura (Unevenness/Variation): Fluctuations in workload, scheduling, or quality.
• Muri (Overburden): Pushing machines or people beyond their natural limits.
• Muda (Waste): Activities that consume resources but do not add value (e.g., overproduction, waiting, inventory, defects).

Heijunka directly attacks Mura. By leveling the workload, it prevents the Muri that results from sudden peaks. And by eliminating Mura and Muri, it significantly reduces many forms of Muda, particularly overproduction and excessive inventory. It creates the stable foundation upon which other Lean improvements can be built.

The Two Pillars of Heijunka: Volume and Type Leveling

Heijunka implementation has been shown to be a competitive advantage in various industries (manufacturing, agriculture, construction, automotive, textile) and can also be applied in service companies (hospitals) (Boutbagha and El Abbadi, 2023).

Production leveling achieves production smoothing through two main methods, which can be used independently or, more commonly, together:

Volume Leveling: Producing a Constant Daily Quantity

This is the simplest form of Heijunka. It focuses on producing a constant total quantity of products each day (or other established period), even if daily customer orders fluctuate.

How Volume Leveling Works

• Calculate Average Demand: Determine the total demand for a product (or product family) over a specific period (e.g., a week or a month).
• Calculate the Daily Average: Divide the total demand by the number of workdays in that period to get the average daily production target.
• Produce Constantly: Manufacture this average quantity each day, regardless of whether daily orders are higher or lower.
• Buffer Stock: Maintain a small, controlled stock of finished goods inventory to handle days when demand exceeds the leveled production quantity. Replenish this buffer on days when demand is lower.

Example: Volume Leveling in a Bakery

Imagine a bakery receives cake orders as follows: Monday: 50, Tuesday: 10, Wednesday: 20, Thursday: 30, Friday: 40. Total = 150 cakes/week.

• Without Heijunka: Production mirrors demand, causing chaos on Monday and downtime on Tuesday.
• With Volume Leveling:
  • Average daily demand = 150 cakes / 5 days = 30 cakes/day.
  • The bakery produces exactly 30 cakes each day.
  • On Monday, they fulfill 30 orders and place 20 into a small finished goods buffer.
  • On Tuesday, they fulfill 10 orders from production and take 20 from the buffer (the buffer is now 0).
  • And so on… This creates a predictable workload, stabilizes ingredient ordering, and ensures consistent staffing.

Type (or Mix) Leveling: Producing a Constant Variety

This method addresses situations where multiple product types or variations are manufactured on the same line(s). Instead of producing large batches of Product A, then a large batch of Product B, Type Leveling aims to produce smaller quantities of multiple product types within each production cycle.

How Type/Mix Leveling Works

• Determine the Product Mix Ratio: Calculate the proportion of total demand represented by each product type over a period.
• Establish a Repetitive Sequence: Create a production sequence that reflects this mix ratio and repeats regularly throughout the day or week. The goal is often expressed as EPEI (Every Part Every Interval) – determining how often each part type needs to be produced.
• Small Batch Production: Produce items in this mixed sequence using small batch sizes.

The Importance of SMED (Single-Minute Exchange of Die)

Type leveling requires frequent changeovers between different products. If changeovers are long and inefficient, this approach becomes impractical. Therefore, SMED – a system for drastically reducing changeover times (idealmente to single-digit minutes), meaning “Single-Minute Exchange of Die” – is often a critical prerequisite for effective Type Leveling. Quick changeovers minimize downtime and make small batch production economical.

Example: Product Mix Leveling in Automotive Manufacturing

Consider a simplified car plant that manufactures Sedans (S), Trucks (T), and Vans (V). Monthly demand is 50% Sedans, 30% Trucks, 20% Vans.

• Without Heijunka (Batches): Produce all Sedans for two weeks, then all Trucks for ~1.5 weeks, then all Vans for ~1 week. This leads to large inventories of each type and slow response if demand changes (e.g., a sudden increase in Truck orders).
• With Type Leveling:
  • The ideal sequence could reflect the ratio, perhaps something like: S-S-T-S-V-S-T… repeating throughout the day.
  • If the plant manufactures 100 vehicles/day, the leveled schedule could aim for approximately 50 Sedans, 30 Trucks, and 20 Vans each day, produced in a mixed sequence. This requires quick changeovers between models, but keeps inventory low for all types and allows for a much quicker response to demand changes.

Essential Tools for Heijunka Implementation

Visual management tools are crucial for implementing and maintaining Heijunka. The most prominent is the Heijunka box.

The Heijunka Board (Leveling Box): Visualizing the Schedule

Often called the Heijunka Box or Leveling Box, this is a visual scheduling tool used to manage the leveled production sequence.

What is a Heijunka Board (or Heijunka Box)?

It is typically a physical grid (though digital versions exist) representing the production schedule over a specific timeframe (e.g., a shift or a day).

• Rows: Usually represent different product types or families.
• Columns: Represent regular time intervals (e.g., every 15, 30, or 60 minutes). This interval is often related to the pitch, which is Takt Time multiplied by the pack quantity (how many units are moved to the next process at once).
• Slots/Pockets: Each cell in the grid holds cards, typically Kanban cards, representing small batches of specific products.

How Heijunka Boxes Work: Rows, Columns, and Kanban

• Planning: Planners load the Heijunka box with Kanban cards according to the predetermined leveled sequence (volume and mix) for the upcoming period. The pattern of cards visually represents the smoothed production plan.
• Execution: At the start of each time interval (each column), a material handler or team leader removes the Kanban cards from the corresponding column.
• Signaling: These removed cards signal upstream processes (e.g., assembly, fabrication) exactly what products to produce and in what quantity during that specific time interval.
• Pull System: As finished products are consumed by downstream processes or customers, signals (other Kanbans) trigger the replenishment process, which is guided by the Heijunka box schedule.

The purpose of Heijunka boxes is to provide a clear, real-time visual representation of the leveled production plan, making it easy for everyone to understand what needs to be produced and when.

Examples of Heijunka Boards: Physical vs. Digital

• Physical Boards: Simple, tangible, and highly visible on the shop floor. Often use colored cards or pegs. Excellent for encouraging team engagement.
• Digital Boards: Offer more flexibility, easier updates, integration with ERP/MES systems, and remote visibility. Can automatically track progress.

The choice depends on the operation’s complexity, existing technological infrastructure, and company culture.

Kanban: The Signaling System for Pull Production

Heijunka does not work in isolation; it heavily relies on a Kanban system to function as a “pull” system. Matzka et al. (2012) highlight that Kanban provides the “pull” mechanism and the demand signal through cards (withdrawal and production Kanbans), while Heijunka provides the scheduling and sequencing discipline by organizing and releasing the production Kanbans in a leveled manner through the Heijunka board, thus smoothing the production flow and mix.

How Kanban Supports Heijunka Scheduling

• Withdrawal Kanban: Signal the need to move finished products from inventory to the point of use or shipping.
• Production Kanban: Signal the need to produce more of a specific item to replenish consumed inventory.
• Integration with the Heijunka Box: Kanban cards placed in the Heijunka box are typically Production Kanbans, sequenced according to the leveled plan. When removed at each time interval (pitch), they authorize production. As items are produced and moved, the corresponding Withdrawal Kanbans circulate, eventually triggering the need for more Production Kanbans to enter the Heijunka sequence.

Heijunka provides the plan (what mix and volume over time), while Kanban provides the real-time signals to execute that plan based on actual consumption.

Implementing Heijunka: A Step-by-Step Approach

Implementing Heijunka requires careful planning and a systematic approach.

Step 1: Calculate Takt Time (The Rhythm of Customer Demand)

Takt Time (from German Taktzeit, meaning beat time or rhythm) determines the production pace needed to meet customer demand.

• Formula: Takt Time = Available Production Time per Period / Customer Demand per Period

• Example: If you have 450 minutes of available time per shift and the daily demand is 150 units, the Takt Time = 450 / 150 = 3 minutes per unit. Your production system needs to deliver one unit every 3 minutes on average.

Step 2: Determine the Production Leveling Pattern (EPEI – Every Part Every Interval)

Based on Takt Time, average demand for each product type, and achievable changeover times, determine:

• Volume Leveling: The constant daily/shift production target.
• Type Leveling: The repetitive sequence of product types and the batch size for each within the sequence. This often involves calculating EPEI (Every Part Every Interval) – how often each part number needs to be run.

Step 3: Create the Heijunka Box/Board Schedule

• Design the physical or digital layout of the Heijunka box (rows for products, columns for time intervals/pitch).

• Determine the pitch (the time interval for each column, often a multiple of Takt Time based on standard pack quantities).

• Load the box with Kanban cards representing the leveled production sequence determined in Step 2.

Step 4: Establish Withdrawal Kanban for Finished Goods

• Implement a system (often using Kanban cards) to signal the consumption of finished products.

• Define the controlled inventory quantity of finished goods needed to buffer minor demand variations between production cycles.

Step 5: Implement and Monitor with Continuous Improvement (Kaizen)

• Train teams on how the Heijunka box and Kanban signals work.

• Launch the system.

• Closely monitor performance: Are production targets being met? Is the buffer inventory sufficient but not excessive? Are changeovers running smoothly?

• Use daily management meetings and tools like Value Stream Mapping to identify problems and improvement opportunities (Kaizen). Adjust the leveled schedule and buffer sizes as needed based on performance and changing demand patterns.

Prerequisites for Successful Heijunka Implementation

Heijunka is not a magic wand; it requires certain foundations:

• Process Stability: Underlying production processes must be relatively stable and predictable. Significant quality issues or frequent breakdowns will disrupt the leveled flow.
• Quick Changeovers (SMED): Especially crucial for Type Leveling. Long changeover times make small batch production impractical.
• Standardized Work: Clearly defined and repeatable work procedures are necessary for consistency.
• Workforce Flexibility/Multiskilling: Workers may need to handle different product types or tasks as the mix changes.
• Reliable Equipment (TPM): Total Productive Maintenance helps ensure machines are available when needed according to the schedule.
• Accurate Demand Forecasting: While Heijunka smooths variations, it still relies on a reasonably accurate forecast of average demand over the planning period.

Advantages of Heijunka: Why Leveled Production is Worth It

Implementing Heijunka effectively yields substantial benefits across the entire operation. For example, Yusuf et al. (2024) determined that the production scheduling system using the Heijunka method proved suitable for the automotive manufacturing process, as it distributes production uniformly over a period, avoiding long waiting times for units and minimizing time waste; while Feleafel et al. (2025) highlighted the contribution of the Heijunka strategy to achieving more collaborative and ecological microgrids by enabling energy demand leveling, which in turn reduces unplanned volatility, decreases carbon emissions, and improves overall electrical system stability.

Ramekar et al. (2017) reported that implementing the Heijunka concept brings multiple significant benefits: It results in improved overall productivity, leads to waste elimination, enables cost-effective production and the delivery of only the necessary quantity of parts with the right quality, time, and place, among others. Below we detail the main benefits of implementing Heijunka:

Waste Reduction (Muda): Overproduction, Inventory, Waiting Time

This is perhaps the most significant benefit. By producing closer to actual average demand in smaller, mixed batches, Heijunka drastically reduces:

• Overproduction: The worst form of waste, as it generates other wastes.
• Excessive Inventory: Both finished goods and WIP (Work in Process) are minimized, freeing up capital and space.
• Waiting: A smoother flow reduces downtime for workers and machines.

Increased Stability and Predictability in Operations

A leveled schedule creates a predictable rhythm for the plant, making planning, staffing, and material supply much easier and less stressful.

Lower Inventory Levels and Capital Costs

Less inventory means less capital tied up in unsold goods, lower storage costs, and reduced risk of obsolescence.

Increased Flexibility and Responsiveness to Demand Changes

Although it seems counterintuitive, leveling increases flexibility. By producing smaller batches of different products more frequently, the system can react much faster to changes in customer preferences or order quantities compared to long runs of single products.

Reduction of Overburden (Muri) on Workers and Equipment

Eliminating extreme peaks and valleys in demand reduces the strain on employees and machinery, leading to improved safety, higher morale, better quality, and longer equipment life.

Improved Synchronization Across the Value Chain (Including Suppliers)

Leveling production internally allows sending more stable and predictable demand signals upstream to suppliers, reducing the bullwhip effect and enabling suppliers to also operate more efficiently.

Challenges and Considerations for Heijunka

Although powerful, implementing Heijunka is not without its challenges. It is important to note that Heijunka is not applicable to mass production (continuous, same product) or unit production (unique components); it is only possible to implement it in the production of standard products, produced serially, where workstations have a fixed and immutable production plan (Rewers and Diakun, 2021).

Handling High Demand Volatility

Heijunka works best when demand, although fluctuating daily, shows a reasonably stable average over a slightly longer period (e.g., weekly or monthly). Extremely erratic or unpredictable demand can make leveling difficult, requiring larger buffer stocks or alternative strategies.

Managing Product Variety and Complexity

A large number of product variations (SKUs – Stock Keeping Units) increases the complexity of creating the leveled sequence and necessitates more frequent changeovers.

The Need for Quick Changeovers (SMED)

As mentioned, efficient Type Leveling heavily relies on the ability to perform changeovers quickly (SMED). If changeover times are long, the benefits of small batches can be negated by excessive downtime.

Cultural Change and Workforce Training

Moving from a batch-and-queue mindset to a leveled flow requires significant change management, training, and buy-in from the workforce and management. Operators may need multiskilling to handle different products.

When Heijunka Might Not Be the Best Option

In environments with extremely low volume and very high customization (e.g., engineer-to-order), or where changeover times are inherently very long and cannot be significantly reduced, a pure Heijunka approach might be less applicable, although the principles of reducing Mura remain valuable.

Heijunka vs. Other Concepts: JIT, Kanban, and Batch Production

It is important to understand how Heijunka relates to other common production concepts:

Heijunka vs. Just-In-Time (JIT): Complementary, Not Contradictory

Heijunka and JIT are deeply interconnected pillars of the Toyota Production System.

• JIT: A philosophy focused on producing only what is needed, when it is needed, and in the quantity needed (“Just in Time“). Its goal is to eliminate inventory by having materials arrive “just in time” for processing.
• The Role of Heijunka: Heijunka enables JIT. The leveled, stable production flow created by Heijunka is necessary for a pull system like JIT to function smoothly, without constant disruptions or stock-outs. You can think of Heijunka as creating the stable riverbed that allows the water (JIT flow) to move smoothly.

Heijunka and Kanban: Working Hand in Hand

As discussed previously, Kanban is the signaling mechanism used to execute the leveled plan created by Heijunka in a pull system.

• Heijunka: Defines the plan (sequence and volume over time).
• Kanban: Provides the real-time signals for production and material movement based on actual consumption, following the Heijunka plan.

Heijunka vs. Traditional Batch Production: The Clear Contrast

This is the central comparison:

Heijunka in Lean and Six Sigma

Heijunka is fundamental to both Lean and Six Sigma philosophies, although it is approached slightly differently.

Heijunka as a Cornerstone of the Toyota Production System and Lean

Within Lean, Heijunka is considered essential for achieving flow and eliminating waste. It is not just a tool but a fundamental principle that underpins the stability and efficiency of the entire system. It directly addresses Mura, which is considered the root cause of much of Muri and Muda.

How Heijunka Supports Six Sigma Goals (Variation Reduction)

Six Sigma strongly focuses on reducing variation and defects (often measured by Defects Per Million Opportunities – DPMO). While Heijunka primarily targets production variation (Mura), this stability has positive side effects relevant to Six Sigma:

• Stable Processes: Leveled production allows for a more consistent operation, making it easier to identify and control the sources of process variation that lead to defects.
• Reduction of Muri: Overburden is a known cause of errors and defects. Heijunka reduces Muri.
• Easier Problem Solving: A stable system makes it easier to detect anomalies and effectively apply Six Sigma problem-solving tools (like DMAIC).

While Heijunka Six Sigma is not a standard combined term like “Lean Six Sigma,” the principles are highly complementary. Heijunka creates the stable operating environment where Six Sigma defect reduction tools can be more effective.

Heijunka and Industry 4.0

Kjellsen et al. (2021) highlight that while traditional Lean production leveling methods have proven to improve performance in discrete manufacturing, the process industry has not fully adopted the benefits of Lean manufacturing due to its inherent complexity and inflexibility; however, the researchers argue that Industry 4.0 technologies offer a pathway to overcome these challenges.

Kjellsen et al.’s team (2021) developed a conceptual framework illustrating how the Internet of Things (IoT) and Big Data Analytics can gather information about process industry characteristics that would otherwise hinder the effective application of Heijunka methods.

Conclusion: Achieving Flow and Efficiency Through Heijunka

Heijunka, or production leveling, is much more than an operational tactic; it is a strategic approach to managing production that lies at the heart of Lean thinking. By directly addressing unevenness (Mura), it creates a virtuous cycle: stable workloads prevent overburden (Muri), which in turn drastically reduces waste (Muda) in all its forms, particularly devastating overproduction and excessive inventory.

Summary of Key Heijunka Concepts and Benefits

• Core Idea: Smoothing the production volume and mix over time, despite fluctuating customer orders.
• Methods: Volume leveling and/or type/mix leveling.
• Key Tool: The Heijunka Box/Board used with Kanban signals.
• Main Goal: Eliminate Mura to reduce Muri and Muda.
• Main Benefits: Stability, predictability, reduced inventory, lower costs, shorter lead times, increased flexibility, less waste, and reduced strain on resources and suppliers.

Final Thoughts: Is Heijunka Right for Your Organization?

Implementing Heijunka requires commitment, discipline, and often foundational improvements such as process stabilization and accelerating changeovers (SMED). However, for organizations struggling with the chaos of uneven demand, bulging inventories, long lead times, and overburdened operations, embracing the concept of Heijunka offers a proven path towards greater efficiency, responsiveness, and ultimately, a significant competitive advantage. By embracing production leveling, companies can move away from reactive firefighting and move towards a state of smooth, predictable, and efficient flow.

Frequently Asked Questions (FAQ) about Heijunka

What does Heijunka mean?

Heijunka is a Japanese term that translates roughly as “leveling” or “smoothing.” In the context of Lean manufacturing, it refers to the practice of leveling the production volume and/or mix over a defined period to reduce unevenness (Mura).

What is the main purpose of a Heijunka box?

The main purpose of a Heijunka box (or Heijunka board) is to provide a clear visual representation of the leveled production schedule. It uses rows (for products) and columns (for time intervals) with Kanban cards to show workers exactly what to produce, in what sequence, and when, according to the smoothed plan.

Is Heijunka the same as load leveling?

Yes, Heijunka is essentially the Japanese term for production leveling or load leveling. Both refer to the concept of smoothing the workload over time to create a more constant and predictable production flow.

How does Heijunka reduce inventory?

Heijunka reduces inventory in several ways:

• It Eliminates Overproduction: By producing based on average demand rather than peak demand, it avoids creating excessive stock.
• It Enables Small Batches: Type leveling allows for smaller production runs, reducing Work in Process (WIP) inventory.
• It Requires Less Buffer: While a small buffer of finished goods is often used, it is usually much smaller than the inventory needed in a traditional batch system because production is more predictable and responsive.

Can Heijunka be applied outside of manufacturing?

Yes, the principles of Heijunka (leveling the workload, reducing unevenness) can be applied in various non-manufacturing environments, such as:

• Software Development: Leveling the flow of features or bug fixes across development sprints.
• Healthcare: Smoothing the flow of patients through different departments or scheduling elective surgeries more evenly.
• Service Industries: Leveling appointment schedules or call center staffing based on average demand patterns.
• Project Management: Balancing task allocation among team members over the duration of the project.

What are the prerequisites for implementing Heijunka?

Key prerequisites often include:

• Relatively stable underlying processes.
• Quick changeover capabilities (SMED), especially for Type Leveling.
• Standardized work procedures.
• A functional Kanban or pull system.
• (Sufficiently) accurate demand forecasting for the average period.
• Management commitment and workforce training.

References

Boutbagha, M., & El Abbadi, L. (2023). Heijunka-levelling customer orders: a systematic literature review. International Journal of Production Management and Engineering, 12(1), 31–41. https://doi.org/10.4995/ijpme.2024.19279

Feleafel, H., Leseure, M., & Radulovic, J. (2025). Shifting Towards Greener and More Collaborative Microgrids by Applying Lean-Heijunka Strategy. Eng, 6(4), 69. https://doi.org/10.3390/eng6040069

Gomaa, A. H. (2025). Lean 4.0: A Strategic Roadmap for Operational Excellence and Innovation in Smart Manufacturing. International Journal of Emerging Science and Engineering (IJESE), 13(4), 1-14.

Kjellsen, H.S., Ramillon, Q.J.L., Dreyer, H.C., Powell, D.J. (2021). Heijunka 4.0 – Key Enabling Technologies for Production Levelling in the Process Industry. In: Dolgui, A., Bernard, A., Lemoine, D., von Cieminski, G., Romero, D. (eds) Advances in Production Management Systems. Artificial Intelligence for Sustainable and Resilient Production Systems. APMS 2021. IFIP Advances in Information and Communication Technology, vol 630. Springer, Cham. https://doi.org/10.1007/978-3-030-85874-2_77

Korytkowski, P., Wisniewski, T., & Rymaszewski, S. (2013). Multivariate simulation analysis of production leveling (heijunka) – a case study. IFAC Proceedings Volumes, 46(9), 1554-1559. https://doi.org/10.3182/20130619-3-RU-3018.00285

Matzka, J., Di Mascolo, M. & Furmans, K. Buffer sizing of a Heijunka Kanban system. J Intell Manuf 23, 49–60 (2012). https://doi.org/10.1007/s10845-009-0317-3

Phatale, A. (2020). An essential guide to lean production tools and techniques: Enhancing efficiency and quality in manufacturing. International Journal of Science and Research, 9(11). https://doi.org/10.21275/SR24314023042

Ramekar, A. M., Muneshwar, V. D., Kute, A. S., & Choube, A. M. (2017). Concept of Heijunka. International Advanced Research Journal in Science, Engineering and Technology, 4(3), 219-223.

Rewers P, Diakun J (2021) A heijunka study for the production of standard parts included in a customized finished product. PLoS ONE 16(12): e0260515. https://doi.org/10.1371/journal.pone.0260515

Soliman, Mohammed, Heijunka: The Leveling Art of the Japanese Auto Maker (November 22, 2022). Book, ISBN# 9798215874561, Available at SSRN: https://ssrn.com/abstract=4311938

Yusuf, M. S. N., Fauzi, D. A., Solehudin, S. A., Hidayat, R., & Prastyo, Y. (2024). Implementing Heijunka Improves Production Time Efficiency at PT Toyota. Review: Journal of Multidisciplinary in Social Sciences, 1(13), 540-547.

Milthon Lujan Monja

Editor and founder of “Innovar o Morir” (‘Innovate or Die’). Milthon holds a Master’s degree in Science and Innovation Management from the Polytechnic University of Valencia, with postgraduate diplomas in Business Innovation (UPV) and Market-Oriented Innovation Management (UPCH-Universitat Leipzig). He has practical experience in innovation management, having led the Fisheries Innovation Unit of the National Program for Innovation in Fisheries and Aquaculture (PNIPA) and worked as a consultant on open innovation diagnostics and technology watch. He firmly believes in the power of innovation and creativity as drivers of change and development.