JIT is a philosophy aimed at reducing waste by ensuring the right quantity of materials are delivered to production at the right time. It originated at Toyota and involves continual improvement to optimize processes. The key principles of JIT include minimizing inventory, supplier partnerships to deliver materials as needed, pulling work through production rather than pushing, and reducing setup times. JIT aims to eliminate all non-value adding activities to create an efficient manufacturing process with no waste.

1. Just In Time
Definition
JIT philosophy means getting the right quantity of goods at the right place and the right time.
Uses a systems approach to develop and operate a manufacturing system. Organizes the
production process so that parts are available when they are needed for production. A method for
optimizing processes that involves continual reduction of waste.
JIT originated in Japan at Toyota Motor Co, fueled by a need to survive the devastation post
WWII. JIT gained worldwide prominence in the 1970s. Often termed “Lean Production” or
“Lean Systems”. Broad view that entire organization has the same goal - to serve customers
Just-In-Time manufacturing was originally developed in the Far East and so far they have been
the most successful in implementing it into their production processes. It’s much more than just
another way to control inventory, it’s a way to eliminate it completely. During production parts
and subassemblies are to be available on the shop floor exactly when they are needed. Any part
of the production process that does not add value to the product should be eliminated.
Central Themes
Waste is defined as “any activity that increases cost but does not add value to the product. The
end result should be a manufacturing process with no wasteful actions. The goal of JIT
manufacturing is to identify the perfect process, making the process as simple and efficient as
possible. Quality is one of the main. To adapt to changes in environment
Just-In-Time Techniques
Inventory reduction as a tool for improvements, means that if you reduce inventory many good
things can happen along with it. Costs are reduced greatly if inventory is reduced, also a large
inventory usually does not get rid of problems it just hides them. Supplier relationships is a big
part of the JIT process, the main goal is to have suppliers deliver raw materials and components
exactly when they are needed on the shop floor, skipping inspection and storage. This requires a
great deal of trust between the supplier and the customer, this can be achieved through sole-
sourcing, and long term contracts to promote loyalty. Inventory pull is the opposite of the
traditional technique, inventory push. Inventory pull means that each manufacturing center pulls
the work from the previous site as space becomes available. This keeps the WIP low because
there is no buildup of work at any specific work station. The only WIP needed is the work on
the floor being currently manufactured. Uniform plant loading refers to the fact that the plant
should be making today what the customer ordered for delivery today. An aspect of JIT is to
have a uniform, level schedule of production that can also be very flexible depending on the
demand for the product. There should be level flow of work passing through each work station
throughout the day.

2. Reduced setup times are achieved in JIT by keeping batch sizes as small as possible, the ideal
batch size is said to be one. Companies spend a lot of time in setup time reduction, with the
implementation of JIT setup time are usually reduced thirty or fifty percent. In a Just-In-Time
manufacturing company the plant floors are laid out so that there is a minimal movement of
goods during the production process, this reduces a great deal of waste. Product quality is
extremely important in a JIT situation, all aspects of the product and the manufacturing process
must be carefully scrutinized for optimum quality. Every member of the production process
must be trained in production quality and should use techniques to assure quality. Techniques
such as Statistical process control are a very good way to ensure quality during production.
Preventive maintenance is needed to reduce variation in the process and also to keep a high level
of quality. This requires a comprehensive examination of all machines on a regular basis.
Misconceptions
With the implementation of Just-In-Time techniques inventory will become more controlled but
it is hardly the major function. The “pull” system that JIT uses does not allow inventory to be in
abundance, and materials cannot be ordered until needed. If JIT was implemented as an
inventory control alone it could never be effective. The second major misconception about JIT is
that a company pushes the suppliers inventory back into their shop thus, leaving the supplier with
the heavy inventory load. A business with an effective JIT process should never have an
abundance of inventory no matter where it is stored, whether the inventory is still at the suppliers
or the customer has it is irrelevant, it is still costing to hold it. The final misconception is that
JIT systems are only quality control programs, this is the biggest misconception because JIT is
an operating philosophy not a program for a single facet of operation.
Goals
Design of a product is one of the most important phases of a products development because it
integrates the quality and cost immediately. Designing a product with high manufacturability is
an important step because it shows the efficiency at which a product can be manufactured. To
minimize the resources that go into a product is just good business practices; however, it is a key
to success in JIT systems. Capital, equipment, and labor are the key elements of a product and
the reduction of these will minimize cost and time in the production process, but the important
thing is that the product remains at a high level of quality. Being responsive to the customer’s
needs is also very important in JIT systems because you must be able to understand how your
customers internal systems and requirements. Being responsive to the customer can include;
producing various sizes of lots, reducing manufacturing costs, reducing lead time, reducing the
customer’s internal costs, working with the customer’s management on future products.
Trust and open relationships are very important in a JIT atmosphere because the customer and
the supplier must set long-term goals and very precise shipment and delivery dates. When
working in a JIT system it is not about you it’s about teamwork and helping each is as effective

3. as possible. The last goal is to have a firm-wide commitment to continuous improvement. The
management must encourage and support continuous improvement for JIT to be effective.
Advantages
Materials cost savings is basically the reduction of costs incorporated with purchasing, receiving,
inspection, and stockroom costs. Manufacturing cost savings identifies saving in the
engineering, production, and the quality control activities. A major part of manufacturing cost
savings I keeping a high level of quality, quality reduces cost and increases revenue. Sales cost
saving comes in the form of reducing overlap between the supplier and the customer, which is
inspection and testing. The most effective situation that the sales department can establish is
finding customers that also use JIT systems.
Toyota Production System A Real World Example
The practical expression of Toyota's people and customer-oriented philosophy is known as the
Toyota Production System (TPS). This is not a rigid company-imposed procedure but a set of
principles that have been proven in day-to-day practice over many years. Many of these ideas
have been adopted and imitated all over the world.
TPS has three desired outcomes:
 To provide the customer with the highest quality vehicles, at lowest possible cost, in a
timely manner with the shortest possible lead times.
 To provide members with work satisfaction, job security and fair treatment.
 It gives the company flexibility to respond to the market, achieve profit through cost
reduction activities and long-term
prosperity.
TPS strives for the absolute elimination of
waste, overburden and unevenness in all areas to
allow members to work smoothly and
efficiently. The foundations of TPS are built on
standardization to ensure a safe method of
operation and a consistent approach to quality.
Toyota members seek to continually improve
their standard processes and procedures in order
to ensure maximum quality, improve efficiency
and eliminate waste. This is known as kaizen
and is applied to every sphere of the company's
activities.

4. Kaizen - Continuous Improvement
Kaizen is the heart of the Toyota Production System.
Like all mass-production systems, the Toyota process requires that all tasks, both human and
mechanical, be very precisely defined and standardized to ensure maximum quality, eliminate
waste and improve efficiency.
Toyota Members have a responsibility not only to follow closely these standardized work
guidelines but also to seek their continual improvement. This is simply common sense - since it
is clear that inherent inefficiencies or problems in any procedure will always be most apparent to
those closest to the process.
The day-to-day improvements that Members and their Team Leaders make to their working
practices and equipment are known as kaizen. But the term also has a wider meeting: it means a
continual striving for improvement in every sphere of the Company's activities - from the most
basic manufacturing process to serving the customer and the wider community beyond.
Just In Time
It is perhaps not widely known that the 'just in time' approach to production that has now gained
almost universal acceptance in world manufacturing was actually pioneered by Toyota. In fact, a
Toyota engineer coined the term itself.
This, too, is a simple but inspired application of common sense.
Essentially, 'just in time' manufacturing consists of allowing the entire production process to be
regulated by the natural laws of supply and demand.
Customer demand stimulates production of a vehicle. In turn the production of the vehicle
stimulates production and delivery of the necessary parts and so on.
The result is that the right parts and materials are manufactured and provided in the exact amount
needed - and when and where they are needed.
Under 'just in time' the ultimate arbiter is always the customer. This is because activity in the
system only occurs in response to customer orders. Production is 'pulled' by the customer rather
than being 'pushed' by the needs or capabilities of the production system itself.
The linkage between customer demand and production is made by analyzing takt time, a device
for measuring the pace of sales in the market in relation to the capacity of a manufacturing plant.
For example, if a plant operates for 920 minutes per day and daily demand is for 400 vehicles,
then takt time will be 2.3 minutes.

5. If takt times are reduced more resources are allocated. Toyota never tries to accommodate
changes in demand by making substantial changes in individuals' workloads.
Assigning more Members to a line means that each handles a narrower range of work. Assigning
fewer means that each handles a broader range. Hence the paramount importance of having a
well-trained, flexible and multi-skilled workforce.
Within the plant itself, the mechanism whereby production is regulated in this way is known as
the Kanban.
A Kanban is simply a message. For example, in the assembly shop this message takes the form
of a card attached to every component that is removed and returned when the component is used.
The return of the Kanban to its source stimulates the automatic re-ordering of the component in
question.
Paperwork is minimized. Efficiency is maximized. And the Members themselves are completely
in charge.
Jidoka
In Japanese 'Jidoka' simply means automation. At Toyota it means 'automation with a human
touch'.
In 1902 Sakichi Toyoda invented the world's first automatic loom that would stop automatically
if any of the threads snapped. This principal, Jidoka, of designing equipment and processes to
stop and call attention to problems immediately when they sense a problem is a central concept
of TPS.
The most visible manifestation of 'automation with a human touch' at the Altoona plant is the
Andon cord situated above the line. The presence of the Andon cord permits any Team Member
to intervene and bring production to a halt if abnormalities occur.
The Toyota Production System has inherited the principle originated by Henry Ford of breaking
down work into simple steps and distributing those steps amongst employees on the line. But
employees in the Toyota system are in charge of their own jobs. Through their teams, they run
their own worksites. They identify opportunities for making improvements and take the initiative
in implementing those improvements in co-operation with management.
Just-in-time manufacturing and other elements of the Toyota Production System work best when
they are a common basis for synchronizing activity throughout the production sequence. This is
an egalitarian arrangement in which each process in the production flow becomes the customer
for the preceding process and each process becomes a supermarket to the following process.

6. Independent suppliers participate on an equal footing with Toyota operations in the production
flow, each fulfilling their own role in that flow.
The only participant in the entire sequence who does not answer to anyone is the customer who
selects a vehicle in the marketplace.
Suppliers who participate in the Toyota Production System enjoy the same benefits that Toyota
does from the system. Just-in-time manufacturing can dissolve inventories at parts suppliers just
as readily and effectively as it does at Toyota's assembly plants. Product quality improves, too.
That's because the Toyota Production System includes measures for illuminating defects
whenever and wherever they occur.
Suppliers who adopt the Toyota Production System also report improvements in employee-
management relations. That is mainly because the system provides for an expanded role for
employees in designing and managing their own work. It brings together employees and
management in the joint pursuit of improvements in productivity, quality, and working
conditions.