The Just in Time (JIT) system, known in Spanish as Justo a Tiempo, is an inventory and production management methodology that has transformed the manufacturing industry. This approach, initially developed by Toyota under the umbrella of the Toyota Production System, aims to minimize waste and improve efficiency by producing only what is necessary, when it is necessary, and in the necessary quantity. JIT is a movement that has gained wide acceptance in the business community over the past decades (Taghipour et al., 2020).
Just in Time is a production process approach that works according to demand, avoiding any kind of losses (Balaji et al., 2021); in this way, a well-executed JIT fosters collaboration, reduces response times, improves efficiency (Choi et al., 2023), and has been shown to save a lot of waste for the organization and provide effective savings (Ahsan, 2022).
This article explores in depth the concept of Just in Time (JIT), its history, benefits, and challenges, and how it compares to other inventory and production management methodologies.
What is Just in Time (JIT)?
Lea and Parker (1989) define Just in Time, in Spanish “justo a tiempo”, as “the creation of a flexible environment in which everyone works to eliminate waste and simplify processes so that the overall performance of the company continuously improves.”
On the other hand, Balaji et al. (2021) state that JIT is a form of inventory management in which raw materials are only obtained from suppliers when necessary; while Ahsan (2022) highlights that Just in Time (JIT) is a Lean methodology that provides economic convenience to the organization.
Taghipour et al. (2020) indicate that Just in Time guides a manufacturing company to organize and manage its business more effectively and to plan and control its operations more efficiently. The goal of implementing JIT is to reduce costs and create efficiencies in the supply chain (McCauley, 2020).
It is important to note that Just in Time (JIT), along with value stream mapping, jidoka, kanban, poka-yoke, andon, and visual management, are part of the Lean production philosophy that is based on the concept of maximizing productivity and eliminating waste (Demir and Paksoy, 2023).
History of Just in Time
The origin of Just in Time dates back to Japan in the 1950s when Toyota was looking for ways to compete with the larger, more established automotive manufacturers in the West; however, it was mainly developed in the 1960s and 1970s, introducing concepts such as kanban, with the goal of reducing production time and supplier-to-consumer response time (Krishna and Ulmer, 2020).
Taiichi Ohno, an industrial engineer at Toyota, developed the JIT system as part of the Toyota Production System. Ohno initially began Just in Time as a trial in 1952 with the simple elimination of waste (Stein and Voehl, 1997).
The efficiency achieved by Toyota with JIT attracted the attention of manufacturers worldwide, and in the following decades, many companies adopted and adapted JIT to their own operations.
The philosophy behind JIT is simple: produce what is needed, when it is needed, and in the quantity needed, avoiding any form of waste, whether of time, resources, or materials. For his part, McCauley (2020) states that continuous improvement and waste elimination are the two critical components of the JIT philosophy.
Principles of Just in Time
Just in Time is based on several key principles that seek to optimize the production process and minimize waste:
- Demand-based production: Instead of producing for storage, JIT produces in response to actual customer demand.
- Inventory reduction: Maintaining minimal inventories reduces storage costs and the risk of obsolescence.
- Continuous improvement: The kaizen approach, or continuous improvement, is essential for identifying and eliminating inefficiencies in the production process.
- Quality at the source: Detect and correct defects as they occur to avoid the accumulation of defective products.
- Teamwork: Foster collaboration at all levels of the organization to improve efficiency and quality.
Benefits of Just in Time
Implementing a Just in Time system can provide numerous benefits to organizations. Agrawal (2021) highlights that the Just in Time model allows for an efficient supply chain to offer lower costs throughout the manufacturing process, and these lower costs are passed on to the customer, so the customer is also happy to get good quality at a reasonable cost.
The results of the research by García and Rodríguez (2024) indicate a strong positive correlation between the implementation of Just in Time and the improvement of financial results, demonstrating that JIT significantly contributes to both operational efficiency and financial health.
The main benefits of Just in Time include:
Cost Reduction
By minimizing inventories and reducing waste, companies can significantly lower their operating costs. JIT also helps reduce storage and material handling costs; in this regard, Krishna and Ulmer (2020) highlight that the approach is convenient because it reduces the costs that companies must incur during production to acquire large amounts of inventory and store them as they prepare for production. Pisch (2020) highlights that the associated inventory saving effect is stronger when companies are close to each other so that the supply chain reacts quickly to changes in demand.
Quality Improvement
The focus on quality at the source ensures that problems are identified and resolved quickly, resulting in higher quality products and less rework.
Increased Flexibility
Companies that use JIT can adapt more quickly to changes in market demand, allowing them to be more competitive and better respond to customer needs.
Production Efficiency
JIT optimizes the production process by eliminating wait times and unnecessary movements, increasing efficiency, and reducing the production cycle time. Singh and Singh (2021) evaluated the performance of the strategic implementation of Just in Time practices in medium- and large-scale manufacturing companies in northern India, and concluded that the strategic implementation of the JIT approach significantly improves manufacturing performance.
Challenges of Just in Time
Despite its benefits, implementing Just in Time (JIT) also presents several challenges that companies must address. Choi et al. (2023) indicate that for JIT to work effectively, it is crucial to establish a close and collaborative relationship with suppliers and customers, as well as to reduce geographical distances.
The main challenges of Just in Time are:
Dependence on Suppliers
The success of JIT largely depends on the suppliers’ ability to deliver materials promptly and reliably. Any disruption in the supply chain can negatively affect production.
Risk of Interruptions
The lack of safety inventories can make companies more vulnerable to unexpected disruptions, such as natural disasters, strikes, or logistical problems.
Cultural Change
Adopting JIT requires a significant change in organizational culture. All employees must be committed to the principles of JIT and work together to identify and eliminate waste.
Comparison with Other Inventory and Production Management Systems
Just in Time is not the only inventory and production management system. Other approaches include mass production, batch production, and lean manufacturing. Each has its own advantages and disadvantages, and the choice of the appropriate system depends on the specific needs and circumstances of each company.
Mass Production
Mass production focuses on producing large quantities of identical products to achieve economies of scale. While it can reduce unit costs, this approach can result in large inventories and higher storage costs.
Batch Production
Batch production involves manufacturing a specific quantity of a product before switching to another. This approach can be useful for companies that produce a variety of products, but it can also result in waiting times and changeover costs.
Lean Manufacturing
Lean manufacturing is a broader approach that incorporates JIT principles but also includes other methods to eliminate waste and improve efficiency. Lean manufacturing focuses on creating value for the customer by eliminating any activity that does not add value.
Implementing Just in Time
Implementing JIT in an organization requires careful planning and a systematic approach. Here are some key steps for a successful implementation:
Initial Assessment
Before implementing JIT, it is important to conduct a thorough assessment of current operations to identify areas for improvement and determine the feasibility of JIT.
Training and Development
All employees should receive training on JIT principles and practices. This includes not only production line workers but also managers and other staff members.
Collaboration with Suppliers
Establishing strong relationships with suppliers is crucial for the success of JIT. Companies should work closely with their suppliers to ensure timely delivery and quality of materials.
Monitoring and Continuous Improvement
Once implemented, the JIT system should be continuously monitored to identify areas for improvement. Continuous improvement is an essential component of JIT, and companies should be willing to adjust and refine their processes continually.
Case Studies: Successes and Failures of Just in Time
The Just in Time method has been applied in different industry sectors to ensure that products are only received when needed, thereby minimizing waste and improving efficiency (Krishna & Ulmer, 2020). Agrawal (2021) highlights that the Just in Time model can be implemented in any type of manufacturing industry, including fast-food restaurants, publishing industries, etc., but is widely used in the four-wheeler manufacturing industry.
Numerous companies have successfully implemented JIT, achieving significant improvements in efficiency and quality. However, there are also cases where JIT implementation has failed due to inadequate planning or lack of commitment.
Toyota
Toyota is the most prominent example of JIT success. Thanks to this system, Toyota was able to compete effectively in the global market and become one of the largest automobile manufacturers in the world. The efficiency and quality achieved through JIT have been key to its continued success.
Dell
Dell implemented a JIT system for its computer assembly operations, which allowed it to reduce inventories and deliver customized products to customers quickly and efficiently. This strategy helped Dell become a leader in the personal computer industry.
Boeing
In the 1990s, Boeing faced significant problems with JIT implementation due to the complexity of its supply chain and lack of coordination with suppliers. Although it eventually overcame these challenges, Boeing’s experience highlights the importance of careful planning and collaboration in JIT implementation.
Advantages and Disadvantages of Just in Time
Krishna & Ulmer (2020) report that JIT offers a range of advantages and disadvantages for companies, including the ability to sell without the need for additional inventory. The following table provides a description of the advantages and disadvantages of implementing the Just in Time method:
| Aspect | Advantages | Disadvantages |
| Inventory | – Reduction in storage and handling costs. | – Risk of supply chain interruptions. |
| – Less need for storage space. | – Dependence on reliable and fast suppliers. | |
| Efficiency | – Improvement in operational and production efficiency. | – Can increase pressure on employees and processes. |
| – Reduction of waste and overproduction. | – Requires precise and coordinated management. | |
| Flexibility | – Ability to quickly respond to changes in market demand. | – Less room for errors or unexpected changes. |
| Quality | – Encourages continuous process improvement. | – Errors can have a greater and more immediate impact on production. |
| Costs | – Reduction in operational and financial costs. | – Initial investment in technology and training. |
| – Less capital tied up in inventories. | – Possible cost increases in situations of shortage or delivery delays. | |
| Supplier Relations | – Strengthening relationships with key suppliers. | – Critical dependence on timely suppliers and logistics. |
| Production Control | – Better control over production and reduction of cycle times. | – Can result in problems if fluctuating demand is not adequately managed. |
| Social and Environmental Responsibility | – Lower environmental impact due to waste reduction. | – Difficulty in handling unexpected demands, which can affect customer satisfaction. |
Implementing the “Just in Time” approach can bring many benefits in terms of efficiency and cost reduction, but it also carries significant risks that require careful management and adequate infrastructure.
The Future of Just in Time
Just in Time remains a relevant and valuable methodology in inventory and production management. With advancements in technology, such as automation and data analysis, JIT can evolve and improve even further. Peron et al. (2021) studied how I4.0 technologies can enhance lean practices for Just in Time manufacturing and suggest technology-based improvements for lean practices within Just in Time manufacturing.
Automation and Technology
Automation and emerging technologies, such as the Internet of Things (IoT) and data analysis, can further optimize JIT. For example, automated systems can track and manage inventories in real-time, improving accuracy and reducing the risk of disruptions.
Sustainability and Social Responsibility
JIT can also contribute to sustainability by reducing waste and optimizing resource use. Companies that implement JIT can improve their environmental footprint and demonstrate their commitment to social responsibility. In this regard, Moreira (2022) highlights that Just in Time production, along with continuous improvement, has the potential and indeed provides a possible route to eco-efficient plant operations.
Conclusion
Just in Time is a powerful methodology that has transformed the way companies manage their inventories and production processes. Although it presents challenges, the potential benefits in terms of efficiency, quality, and flexibility are significant. When comparing JIT with other inventory and production management systems, it is important to consider the specific needs of each company and its ability to implement and maintain the system.
With proper planning, commitment, and collaboration, Just in Time can be a valuable tool for any organization seeking to improve its efficiency and competitiveness in the global market. Ahsan (2022) concludes that small businesses should practice the JIT methodology, which is convenient to use, sensible, and easy to implement in the organization.
References
Ahsan Siddiqui. 2022. The Importance of Just in Time (JIT) Methodology and its Advantages in Health Care Quality Management Business – A Scoping Review. Biomed J Sci & Tech Res 42(1)-2022. BJSTR. MS.ID.006701.
Agrawal, N. (2021). Analytical study of just-in-time manufacturing system. International Journal of Advances in Social Sciences, 9(2), 79-82.
Balaji, K. C., Gopal, P., & Rashmi, S. 2021. Continuous improvement in just in time manufacturing (JIT), a systematic literature review. International Journal of Engineering Applied Sciences and Technology, 2021, Vol. 6, Issue 2, ISSN No. 2455-2143, Pages 77-94
Choi, T. Y., Netland, T. H., Sanders, N., Sodhi, M. S., & Wagner, S. M. (2023). Just‐in‐time for supply chains in turbulent times. Production and Operations Management, 32(7), 2331-2340. https://doi.org/10.1111/poms.13979
Demir, S., & Paksoy, T. (2023). Just-in-time and lean management. In Smart and Sustainable Operations and Supply Chain Management in Industry 4.0 (pp. 223-236). CRC Press. h
García-Cutrín, J.; Rodríguez-García, C. Enhancing Corporate Sustainability through Just-In-Time (JIT) Practices: A Meta-Analytic Examination of Financial Performance Outcomes. Sustainability 2024, 16, 4025. https://doi.org/10.3390/su16104025
Krishna, G. M., & Ulmer, J. M. (2020). Just-in-time: an industrial analysis. Future, 4(10), 501-506.
McCauley, M. (2020). Just-in-time inventory: does it fit into all supply chains?.
Moreira, F. (2022). Just-in-Time Production and Eco-efficiency. In: The Palgrave Handbook of Global Sustainability. Palgrave Macmillan, Cham. https://doi.org/10.1007/978-3-030-38948-2_106-1
Peron, M., Alfnes, E., Sgarbossa, F. (2021). Best Practices of Just-in-Time 4.0: Multi Case Study Analysis. In: Wang, Y., Martinsen, K., Yu, T., Wang, K. (eds) Advanced Manufacturing and Automation X. IWAMA 2020. Lecture Notes in Electrical Engineering, vol 737. Springer, Singapore. https://doi.org/10.1007/978-981-33-6318-2_79
Pisch, Frank (2020) Managing global production: theory and evidence from just-in-time supply chains. CEP Discussion Papers (1689). Centre for Economic Performance, LSE, London, UK.
Singh, J., & Singh, H. (2021). Strategic implementation of just-in-time practices for enhancing the performance of manufacturing industry-an empirical investigation. International Journal of Manufacturing Technology and Management, 35(4), 369-388.
Stein, M., & Voehl, F. (1997). Just-In-Time (JIT)/JIT II™. In Macrologistics Management (pp. 149-173). CRC Press.
Taghipour, A., Hoang, P., & Cao, X. (2020). Just in time/lean purchasing approach: an investigation for research and applications. Journal of Advanced Management Science, 8(2).
