The Theory, Advantages and Disadvantages of Just-In-Time Manufacturing

By Protolabs

In the fast-paced world of manufacturing, efficiency is paramount. Among the many strategies employed to streamline production processes, one stands out for its promise of lean operations and optimised inventory management: just-in-time (JIT) manufacturing. Our engineers are well acquainted with this theory, but understanding its intricacies, advantages, and potential pitfalls requires careful consideration. In this blog, we'll explore the theory, advantages, and disadvantages of JIT manufacturing, dissecting how it reshapes the landscape of digital manufacturing and challenges engineers to rethink traditional paradigms. 

Protolabs US manufacturing plant

Decoding the Theory and Impact of Just-in-Time Manufacturing 

JIT Manufacturing, it's more than just a buzzword. It is a whole strategy and process that requires careful planning, consideration, and maintenance. But what is JIT manufacturing, and how can a business benefit from it? 

JIT manufacturing (a key component of lean production) is the process of receiving goods/stock only as it is needed. The strategy aims to reduce waste and minimise inventory levels and associated costs. 

It is made up of some key principles, 

  • Pull Production – Production driven by customer demand rather than traditional methods such as forecasting. This ensures that only items that are needed are produced.
  • Continuous Flow – A smooth, uninterrupted flow of materials and processes to minimise waiting times and bottlenecks.
  • Zero Inventory – Inventory levels are kept as low as possible, with materials arriving just in time for production. Finished goods are then shipped immediately to customers.
  • Quality Control – Focus on producing high-quality products through preventative maintenance, defect prevention and continuous improvement.


What are the advantages of adopting a JIT manufacturing model? 

There are many benefits to a JIT manufacturing model. For example, 

  • Reduced storage costs – due to reduced inventory.
  • Reduced storage requirements – as above.
  • Increase in responsiveness to customer demand.
  • Identification and elimination of excess waste – created by overstocking.
  • Overall improved production efficiency.
  • Improved cash flow – less money spent on stock that potentially doesn’t go.
  • Improved Supplier Relationships – Due to closer collaboration and communication.


moulding machines

What are the downsides of JIT manufacturing? 

Whilst that all sounds fantastic, there are limitations to JIT manufacturing. For example, 

  • Lack of Buffer Stock – Leaving little room for error and increasing the risk of being out of stock.
  • Dependency on Suppliers – relying on suppliers for timely deliveries. Any supply chain disruptions could be problematic.
  • Potential for Production Disruptions – e.g. unforeseen circumstances such as natural disasters, COVID, etc.
  • Increased Administrative Costs – Requiring meticulous planning, coordination, and real-time tracking.
  • Demands Forecasting Accuracy – inaccurate readings could lead to shortages or excess; both would undermine the benefits of JIT.


Are there any alternatives to just-in-time production? 

JIT manufacturing is, of course, not the only option out there. There are various options, including, 

  • Just-in-case (JIC) manufacturing - Maintaining higher inventory levels to cushion supply chain distributions, demand fluctuations, and production uncertainty.
  • Agile manufacturing – this emphasises flexibility and responsiveness to changing market demands. It involves rapidly responding to customer requirements and having collaborative and adaptive partnerships with supply chains.
  • Theory of Constraints (TOC)—The Focus shifts to identifying and managing any potential bottlenecks that could limit the overall production process. Once the bottleneck is identified, other processes may be called in to support it, and the capacity for the bottleneck may be increased.
  • Demand-Driven Manufacturing – Production and inventory are aligned with actual customer demands. This is done using advanced analytics and real-time data.

In the world of manufacturing, where the pace is fast, and efficiency is key, JIT stands out for its fit with lean production principles and optimised inventory management. JIT proves a great option for businesses that want to keep storage, inventory costs and waste down whilst holding strong collaborative relationships with its (ideally local) suppliers. 

Tagged: Just-in-Time