Just In Time (JIT)

1 Introduction

Just-in-time (JIT) is easy to grasp conceptually, everything happens just-in-time. For example consider my journey to work this morning, I could have left my house, just-in-time to catch a bus to the train station, just-in-time to catch the train, just-in-time to arrive at my office, just-in-time to pick up my lecture notes, just-in-time to walk into this lecture theatre to start the lecture. Conceptually there is no problem about this, however achieving it in practice is likely to be difficult!

So too in a manufacturing operation component parts could conceptually arrive just-in-time to be picked up by a worker and used. So we would at a stroke eliminate any inventory of parts, they would simply arrive just-in-time! Similarly we could produce finished goods just-in-time to be handed to a customer who wants them. So, at a conceptual extreme, JIT has no need for inventory or stock, either of raw materials or work in progress or finished goods.

2 Areas of JIT

Initially JIT aimed at manufacturing process improvement. Therefore even today people call JIT as JIT manufacturing. But actually JIT consist of three main parts. They are known as JIT purchasing, JIT manufacturing and JIT distribution.

1. JIT purchasing
   JIT purchasing aims in making sure all the required raw materials in house when they are just required. This functionality is supported with limited supplier bases and agreements with them. Quality is assured in the purchased raw materials.

2. JIT Manufacturing
   Manufacturing the goods when they need is the aim of JIT manufacturing. The need to manufacture is created by the customer demand for the organization, and by the next activity in the manufacturing floor. Production is carried out with no interruptions and with no work in progress. This enables the smooth manufacturing process and flexibility. Many techniques and tools are used in achieving this. Some of them are kanban cards, 5S techniques etc.

3. JIT Distributing
   Just in time process distribute the goods in small batches. Several batches may be sent to the same place even within a day. Goal of this is facilitating the no working progress and large storage concept. This enables the JIT manufacturers to compete on the lead-time and on time delivery. This also cuts down the cost of carrying inventory. In the bigger picture JIT distribution helps the organization.

References

1. Just In Time in Ford
2. JIT of OR-Notes