Explain in brief the origins of Just In Time. Explain the different types of wastes that can be eliminated using JIT.

Just In Time
JIT is a manufacturing/delivery process where a minimum of goods are kept in stock. Items are planned to arrive precisely at the time they are required for use or despatch. JIT can be considered to be a philosophy of manufacturing founded on the principles of elimination of all waste and thereby increasing productivity. When the philosophy is applied at workplace, the approach results in providing parts in just right quantities at the right time. This results in economy of material and time thus lowering the costs and increasing productivity. Since no extra parts are available, production of only good parts is forced on the system. JIT has been extended to mean continuous improvement. These principles are being applied to engineering, purchasing, accounting and data processing also. In these days when technology is able to provide us with highly accurate equipments which have high capacities and the business has become global meaning that both suppliers and customers are widely accessible. To remain competitive, cost efficiencies have become compulsory. JIT helps in this process. It is extended to the shop floor and inventory systems of the vendors also. 

Origin of JIT
Just In Time, or JIT, was coined to name and describe a manufacturing processes developed by Toyota in Japan in the 1950s and which spread to the US and UK in the 1970s. Within Toyota Taiichi Ohno is most commonly credited as the father/originator of this way of working. The beginnings of this production system are rooted in the historical situation that Toyota faced. After the Second World War the president of Toyota said "Catch up with America in three years, otherwise the automobile industry of Japan will not survive". At that time one American car worker produced approximately nine times as much as a Japanese car worker. Taiichi Ohno examined the American industry and found that American manufacturers made great use of economic order quantities - the traditional idea that it is best to make a "lot" or "batch" of an item (such as a particular model of car or a particular component) before switching to a new item. They also made use of economic order quantities in terms of ordering and stocking the many parts needed to assemble a car. Nevertheless, the credit for the initiative should go to Henry Ford. He described essentially the same process, although it wasn't then named, in his autobiography My Life and Work, 1922:
Kanban System
Kanban for material flow Kanban means a ‗Visible Card‘ and also ‗Signal‘ in Japanese language. These cards are used for communicating the quantities required at the ‗customers‘ point for his use. This means that by the card the operator next in line, who is the customer, decides how many units he needs and asks for them. The operator who receives the card should make only that many and supply. Similarly he makes a demand on his predecessor by a ‘kanban‘ and receives only the required quantity. This is called the pull system. The containers are designed to hold specific components in certain numbers. Kanban system is a physical control system which uses cards and containers materials must not be removed without posting a card at the receiving post.
Wastes that can be eliminated using JIT
Taichi Ohno, a production engineer with Toyota Corporation identified seven wastes to be addressed by the Toyota system, and they have become known as the 7Ws which are detailed below:
1. Defects
The simplest form of waste is components or products that do not meet the specification. We all know about the Japanese scaring us with their target of single-figure reject rates when we realised that they measured in parts per million and that 1% defects gave a figure of 10,000.
2. Over-Production
A key element of JIT was making only the quantity required of any component or product. This challenged the Western premise of the Economic Order Quantity (EOQ) which was built on acceptance of fixed ordering costs, built around set-up times, and thus the need to spread these fixed costs over large batches.
3. Waiting
Time not being used effectively is a waste - we are incurring the cost of wages and all the fixed costs of rent, rates, lighting and heating so we should use every minute of every day productively. Ohno looked at the reasons for machines or operators being under-utilised and set about addressing them all.
4. Transporting
Items being moved incur a cost, if it is only the energy needed to initiate the movement - such as the electricity absorbed by a fork lift truck. Of course, movement brings another cost, which is less visible but more significant.
5. Movement
On a related note, people spending time moving around the plant is equally wasteful. The time a machine operator or fitter wastes walking to the tool room or the stores for a fixture or a component could be far better utilised if our plant layout and housekeeping were geared around having everything that is required close to hand.
6. Inappropriate Processing
The most obvious example of inappropriate processing from my own experience relates to surface finishes that required components to be moved to grinders for completion, when in fact such finishes served no purpose.
7. Inventory
The element that Western industry immediately focused upon when confronted with JIT was the cost reduction available from holding less inventory.
In fact, other forms of waste have been identified in Lean definitions since the term was first adopted, though strict devotees of the TPS have been known to dispute matters. Womack and Jones, the leaders of the MIT Study, added that of designing and making products which do not meet the customer's requirements, though this could perhaps be classified within Ohno's Inappropriate Processing. As ever, we can debate the semantics and draw clever diagrams to show how matters overlap, or we can get on with bringing about change for the better within our organisation. I hope that people who know me would recognise the camp to which I belong.