Just in Time (JIT) production is one of the key concepts of Lean Management. This approach has transformed modern manufacturing and logistics, showing companies worldwide the potential of waste elimination and process flow improvement. In this in-depth article, you’ll learn about the history, principles, applications, benefits, and challenges of JIT.
What is Just in Time?
Just in Time (literally “exactly on time”) is a production organization system in which materials, semi-finished products, and components are delivered to the production line or point of use exactly when they are needed—neither earlier nor later.
The key idea behind the Just in Time system is to avoid stockpiling and reduce storage-related costs.
JIT is a response to problems such as overproduction, warehouse congestion, waste, and process inefficiencies.
The History of the Justin Time System
The JIT system was developed in Japan after World War II, mainly by Toyota. The key figure behind it was Taiichi Ohno, who designed a production system in which each step in the process received materials and information exactly when they were required.
Post-war Japan lacked resources for large warehouses or overproduction—hence JIT became the perfect solution. Toyota became the pioneer in implementing this concept, and the success of the Japanese industry inspired Western companies to adopt these principles.
In the 1980s and 1990s, JIT spread across the world. In the West, it was often complemented by Kaizen, Kanban, and Total Quality Management (TQM). Just in Time became the foundation of Lean Manufacturing, which promotes waste elimination and maximizing customer value.
Principles of the Just in Time System
JIT is based on several fundamental principles:
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Produce Only What Is Needed
This principle eliminates overproduction, which generates unnecessary costs and inventory. Production begins only after a demand signal is received. -
Minimize Inventory
The goal is near-zero inventory levels. Warehousing is kept to a minimum, and components are delivered exactly when needed. -
Eliminate Waste
JIT aims to remove all forms of waste (muda), such as overproduction, waiting, unnecessary transport, overprocessing, excess inventory, unnecessary motion, and defects. -
Smooth Flow of Materials and Information
Processes should be designed so that materials and information flow smoothly through the organization, without stoppages or delays.
Just in Time in Practice – Applications
1. JIT in Manufacturing
JIT has revolutionized manufacturing by enabling:
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reduced warehouse space,
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lower material losses,
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faster response to demand changes,
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shorter production cycles.
2. JIT in Logistics
The Just in Time system also changes how logistics works. Suppliers must deliver components with extreme precision—often several times per day, within defined time windows.
3. JIT in Services
Although JIT is mostly associated with manufacturing, its principles can also be applied in services such as hospitality, catering, or healthcare. Eliminating waste and delivering value exactly when the customer needs it is a universal concept.
Tools Supporting Just in Time
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Kanban
Kanban boards and cards visualize demand and control material flow. Kanban acts as a system of “signals” triggering production or delivery. -
Heijunka – Production Leveling
Heijunka helps make processes more stable and predictable. Production runs at a steady pace rather than in peaks and troughs. -
SMED – Single Minute Exchange of Dies
Reducing setup time allows quicker responses to demand changes and increases process flexibility. -
Standard Work
Standardizing operational processes simplifies management, training, and deviation detection.
Benefits of the Just in Time System
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Lower storage costs – no need to hold large amounts of inventory.
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Greater flexibility – quick response to market changes.
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Better quality – smaller production batches improve quality control.
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Higher productivity – smoother flow and fewer stoppages.
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Employee engagement – JIT fosters a culture of continuous improvement and teamwork.
Challenges and Risks of Just in Time
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No Inventory = Higher Risk of Disruptions
While low inventory reduces costs, it increases the risk of production stoppages in case of supplier delays. -
High Supplier Requirements
Suppliers must be reliable, flexible, and capable of frequent, punctual deliveries. -
Complex Coordination
JIT demands precise planning, logistics, and interdepartmental communication. -
Risk During Global Disruptions
The COVID-19 pandemic exposed JIT’s weaknesses—lack of inventory can paralyze operations during extraordinary events.
Just in Time and Lean Manufacturing
JIT is one of the pillars of Lean Manufacturing. Its goal is to deliver what the customer wants, when they want it, and in the quantity they need—without waste. JIT works hand in hand with other Lean concepts such as:
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Kaizen – continuous improvement,
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5S – workplace organization,
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Poka Yoke – error proofing,
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Andon – visual problem signaling.
Examples of JIT Implementation
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Toyota
Toyota is the benchmark example of JIT in action. This system has enabled the company to achieve exceptional efficiency, quality, and production flexibility. -
Dell
Dell revolutionized the computer market by assembling products to order. Components arrived just in time, reducing inventory and enabling mass customization. -
McDonald’s
Although not a manufacturer, McDonald’s also applies JIT principles—preparing food only after an order is placed, reducing waste, and ensuring freshness.
Just in Time vs. Just in Case
JIT minimizes inventory and focuses on real-time production. In contrast, Just in Case (JIC) involves holding large stockpiles “just in case.” Both systems have pros and cons:
| Feature | Just in Time | Just in Case |
|---|---|---|
| Inventory | Minimal | High |
| Shortage Risk | Higher | Lower |
| Storage Cost | Low | High |
| Demand Response | Fast | Limited |
| Flexibility | High | Low |
The choice between JIT and JIC depends on the industry, product type, and available resources. Some companies use a hybrid approach—JIT for key components and JIC for critical parts.
The Future of JIT: Digitalization and Industry 4.0
Modern technologies are taking JIT to new levels. With IoT (Internet of Things), AI (Artificial Intelligence), Big Data, and predictive analytics, companies can plan production and deliveries with unprecedented precision. Real-time systems monitor inventory, transport, production, and demand, enabling automatic responses to changes.
In an era of global crises (such as pandemics or supply chain disruptions), companies are increasingly investing in flexible and diversified models—JIT enriched with local buffers and safeguards. The modern JIT approach is not just about eliminating inventory but about building operational resilience.
Learn more about KaizenUp, which uses AI to support managerial decision-making.
Summary
Just in Time is a philosophy that changed the way we think about production and logistics. By focusing on waste elimination, process synchronization, and on-time delivery, JIT helps achieve higher business performance and better customer satisfaction.
Although implementing JIT requires advanced management, technology, and collaboration, the benefits are undeniable. Combined with Lean management tools and process digitalization, Just in Time forms the foundation of a modern, agile production organization.
It’s not just a method—it’s a way of thinking about time, quality, and value.
I am a promoter of Lean Management and the Training Within Industry program. I am a practitioner. I co-create many startups. Since 2015, I have been the CEO of Leantrix - a leading Lean consulting company in Poland, which, starting from 2024, organizes one of the largest conferences dedicated to lean management in Poland - the Lean TWI Summit. Since 2019, I have been the CEO of Do Lean IT OU, a company registered in Estonia that creates the software etwi.io, used by dozens of manufacturing and service companies in Europe and the USA.
Maciej Antosik – management student at Wrocław University of Science and Technology. I support the Leantrix team in carrying out projects. Among other things, I was responsible for implementing the conference application during the Lean TWI Summit. Currently, I am responsible for marketing and also collaborate on the creation of Kaizen UP and Wiktor Wołoszczuk’s podcast.
Outside of my studies and work, I am developing as a personal trainer and train professionally in powerlifting. Sports teach me discipline and consistency, which I also apply in my professional life. What brings me the greatest satisfaction is personal growth and achieving long-term goals that require courage and pushing beyond my own limits.
In my free time, I am passionate about cooking, traveling, and music – these are spaces for me to act creatively and discover new inspirations. I consider myself ambitious and open-minded, always ready for the next challenge.
