Just In Time (JIT)

Just in time (JIT) is a production strategy that strives to improve a business return on investment by reducing in-process inventory and carrying costs. Moreover, the process depends on signals or Kanban(tickets) between different points. After implementation, JIT focuses on improving manufacturing organization’s return on investment, quality, and efficiency.

In recent years, manufacturers are trying to grind forecasting methods such as applying a trailing 13-week average as a better predictor for JIT planning. Moreover, the philosophy of JIT is simple: the storage of inventory which is not in use is a waste of resources.

JIT Inventory System

JIT inventory systems reveal hidden cost of keeping inventory. Morever, the company must follow an array of new methods to manage the consequences of the change. Above all, the ideas in this way of working come from many different disciplines including statistics, industrial engineering, production management, and behavioral science.

The JIT inventory ideology explains how we can view inventory and how it relates to management. Moreover, inventory is seen as incurring costs, or waste, instead of adding and storing value, contrary to traditional accounting. Above all, this way of working motivates businesses to remove inventory. That is to say, there is a need to improve those processes to require less inventory.

Moreover, management may tempt to keep stock to hide production problems. And, these problems include backups at work centers, machine reliability, process variability, lack of flexibility of employees and equipment.

Types of Inventories

JIT have three types of inventory,

• First, Raw materials inventories.
• After that, Work in process inventories.
• Lastly, Finished goods inventories.

Aims of JIT

The main purpose of JIT is to produce and deliver,

• Firstly, goods finish just in time to be sold
• Then, sub-assemblies just in time to assemble into finished goods
• After that, fabricated parts just in time to go into final assemblies
• Lastly, materials to be purchase just in time to be transformed into fabricated parts.

Moreover, in some manufacturing companies JIT has a name that is ‘continuous flow production’, which describes very well the objective of achieving conversion of purchased material. And, if this extends into the supplier and customer chains then , all operating with JIT continuous flow of material, achieving information or service.

The JIT concepts identify operational problems by tracking the following:

• Material movements
• Material accumulations
• Process flexibility
• Value-added efforts

JIT Operations

The tools to carry out the monitoring includes familiar quality and operations management methods, such as:

• Flowcharting.
• Process study and analysis.
• Preventive maintenance.
• Plant layout methods.
• Standard design.
• Statistical process control.
• Value analysis and value engineering.

But some techniques are more directly connects to the operation of JIT systems:

• Batch or lot size reduction.
• Flexible workforce.
• Kanban or cards with material visibility.
• Mistake-proofing.
• Pull-scheduling.
• Set-up time reduction.
• Standard containers.

JIT Benefits

• Firstly, using funds in inventories elsewhere.
• Secondly, using areas which store inventories can be used for other more productive uses.
• And, throughput time becomes less, resulting in greater potential output and quicker response to customers.
• Lastly, less defect rates, resulting in less waste and greater customer satisfaction.

In operations of JIT, daily activities are take place in order with the continuous appeal of inventory of the final product on the customers demand. Moreover, this aims lead the production program to apply production investments, workers, and even re-ordering raw materials from suppliers. In short, JIT needs a production which depends directly on the patterns of customer’s demands.

The Kanban system

• Kanban is a Japanese term refer as a sign board or a visual signals that authorize the production or movement of items in manufacturing environment.
• Above all, Kanban system is a self-adjusting pull system that leads to shorter lead times and reduce inventory.
• Moreover, applying Kanban systems to items that have relatively constant demand and medium-to-high production volume.
• Kanban works on the basis that each process on a production line pulls just the number and type of components the process requires at that time.
• Kanban systems focus on stopping overproduction thus, preventing creation of large inventories and reducing waste.

Above all, Kanban is a card with an inventory number on it and before installation, the kanban card is detached and sent up the supply chain as a request for another part. Moreover, inventory uses kanban where Kan means color and Ban means card.

Kanban accepted rules

• Firstly, downstream processes may withdraw items in the amounts on the kanban card.
• And, Upstream processes may send items downstream as per quantity and sequence as per kanban.
• No items are made without a kanban.
• A kanban must accompany each item at all times.
• Defects and incorrect amounts are never sent to the next downstream process.
• Lastly, monitor the number of kanbans carefully to reveal problems and opportunities for improvement.

Kanban Working

• Kanban starts with the customer’s order and follows production downstream. Because pull all the requests for parts from the order, kanban is sometimes known as a “pull” system.
• Moreover, Kanbans represent replenishment signals that are usually manual and highly visible such as a color card with code that moves with the material. In this, a light goes on when there is requirement of replenishment.
• In this, the system provides support for external devices such as bar code readers to read kanban cards and trigger a replenishment signal.
• Above all, source Kanbans from an external supplier or an internal organization.  Here, a “Supplier” kanban triggers a purchase request to the supplier, while an “inter-org” kanban results in an inter-organization transfer.
• Kanbans are generally replenishable and cycle through the system from full to empty, remaining active until they are withdrawn. One-time signals known as non-replenishable kanbans are used primarily to manage sudden spikes in demand.

Just in time in Partnerships and the Supply chain

JIT Production

• Effective control of materials and components flow in producing and assembling lines is a key for effective production. Moreover, in an optimal supply chain, receiving all materials and components  in time to lead to a precise production. Here, precise production means producing a safe efficient product in a proper place and time with the least costs.
• In recent years, many achievements have been got to increase production operation outcome and to get an optimal supply chain, among which “Just In Time Production” system is the core.
• Above all, “just in time production” system has got much more attentions in the world industrial societies.

JIT Suppliers

• The development of long-term partnerships with a few suppliers, rather than short-term ones with many, leads to the concept of co-producers in networks of trust providing dependable quality and delivery of goods and services.
• Moreover, each organization in the chain of supply often extend JIT methods to its suppliers. And, the requirements of JIT mean that suppliers are usually near the purchaser’s premises, delivering small quantities to match the usage rate.
•  Above all, if the loctaion of suppliers requirement is near the buying organization it causes lead times to be shorter and deliveries to be more reliable.

JIT Manufacturers

• By minimizing inventory, JIT frees up resources to employ elsewhere in the company. Moreover, a retail store using JIT can remodel the warehouse space into more retail sales floor space.
• Above all, a manufacturer gets more space to produce goods. And, both companies free the workforce to focus on making goods to interacting with customers rather than stocking merchandise.
• Moreover, Manufacturers can train employees to work at different stages of the assembly line or at different workstations, to meet shifts in demand.
• Most importantly, a flexible workforce focusing on quality production can result in faster customization of workstations and lower defect rates. Therefore, it will lower the costs and increase customer satisfaction.

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