pritika new
Post on 05-Apr-2018
222 Views
Preview:
TRANSCRIPT
-
8/2/2019 Pritika New
1/25
Just-in-time (JIT)
Introduction:
Just-in-time (JIT)is defined in the APICS dictionary as a philosophy of
manufacturing based on planned elimination of all waste and on continuous
improvement of productivity. It also has been described as an approach with the
objective of producing the right part in the right place at the right time (in other
words, just in time).
Waste results from any activity that adds cost without adding value, such as the
unnecessary moving of materials, the accumulation of excess inventory, or the use offaulty production methods that create products requiring subsequent rework. JIT (also
known as lean production or stockless production) should improve profits and return
on investment by reducing inventory levels (increasing the inventory turnover rate),
reducing variability, improving product quality, reducing production and delivery lead
times, and reducing other costs (such as those associated with machine setup and
equipment breakdown). In a JIT system, underutilized (excess) capacity is used
instead of buffer inventories to hedge against problems that may arise.
JIT is not about automation. JIT eliminates waste by providing the environment to
perfect and simplify the processes. JIT is a collection of techniques used to improve
operations It can also be a new production system that is used to produce goods or
services.
JIT applies primarily to repetitive manufacturing processes in which the same
products and components are produced over and over again. The general idea is toestablish flow processes (even when the facility uses a jobbing or batch process
layout) by linking work centers so that there is an even, balanced flow of materials
throughout the entire production process, similar to that found in an assembly
line. To accomplish this, an attempt is made to reach the goals of driving all
inventory buffers toward zero and achieving the ideal lot size of one unit.
The basic elements of JIT were developed by Toyota in the 1950's, and became
known as the Toyota Production System (TPS). JIT was well-established in many
-
8/2/2019 Pritika New
2/25
Japanese factories by the early 1970's. JIT began to be adopted in the U.S. in the
1980's (General Electric was an early adopter), and the JIT/lean concepts are now
widely accepted and used.
Some Key Elements of JIT
1. Stabilize and level the MPS with uniform plant loading (heijunka in Japanese):
create a uniform load on all work centers through constant daily
production(establishfreeze windows to prevent changes in the production plan for
some period of time) and mixed model assembly (produce roughly the same mix of
products each day, using a repeating sequence if several products are produced on the
same line). Meet demand fluctuations through end-item inventory rather than through
fluctuations in production level. Use of a stable production schedule also permits the
use ofback flushing to manage inventory: an end items bill of materials is
periodically exploded to calculate the usage quantities of the various components that
were used to make the item, eliminating the need to collect detailed usage information
on the shop floor.
2. Reduce or eliminate setup times: aim for single digit setup times (less than 10
minutes) or "one-touch" setup -- this can be done through better planning, process
redesign, and product redesign. A good example of the potential for improved setup
times can be found in auto racing, where a NASCAR pit crew can change all four
tires and put gas in the tank in under 20 seconds. (How long would it take you to
change just one tire on your car?) The pit crews efficiency is the result of a team
effort using specialized equipment and a coordinated, well-rehearsed process.
3. Reduce lot sizes (manufacturing and purchase): reducing setup times allows
economical production of smaller lots; close cooperation with suppliers is necessary
to achieve reductions in order lot sizes for purchased items, since this will require
more frequent deliveries.
4. Reduce lead times (production and delivery): production lead times can be
reduced by moving work stations closer together, applying group technology and
-
8/2/2019 Pritika New
3/25
cellular manufacturing concepts, reducing queue length (reducing the number of jobs
waiting to be processed at a given machine), and improving the coordination and
cooperation between successive processes; delivery lead times can be reduced through
close cooperation with suppliers, possibly by inducing suppliers to locate closer to the
factory.
5. Preventive maintenance: use machine and worker idle time to maintain equipment
and prevent breakdowns.
6. Flexible work force: workers should be trained to operate several machines, to
perform maintenance tasks, and to perform quality inspections. In general, JIT
requires teams of competent, empowered employees who have more responsibility fortheir own work. The Toyota Production System concept of respect for people
contributes to a good relationship between workers and management.
7. Require supplier quality assurance and implement a zero defects quality
program: errors leading to defective items must be eliminated, since there are no
buffers of excess parts. A quality at the source (jidoka) program must be
implemented to give workers the personal responsibility for the quality of the work
they do, and the authority to stop production when something goes
wrong. Techniques such as "JIT lights" (to indicate line slowdowns or stoppages) and
"tally boards" (to record and analyze causes of production stoppages and slowdowns
to facilitate correcting them later) may be used.
8. Small-lot (single unit) conveyance: use a control system such as akanban(card)
system (or other signaling system) to convey parts between work stations in small
quantities (ideally, one unit at a time). In its largest sense, JIT is not the same thing asa kanban system, and a kanban system is not required to implement JIT (some
companies have instituted a JIT program along with a MRP system), although JIT is
required to implement a kanban system and the two concepts are frequently equated
with one another.
Objective of JIT
1. Produce only the products the customer wants.
-
8/2/2019 Pritika New
4/25
2. Produce products only at the rate that the customer wants them.
3. Produce with perfect quality
4. Produce with minimum lead time.
5. Produce products with only those features the customer wants.
6. Produce with no waste of labor, material or equipment every movement must
have a purpose so that there is zero idle inventory.
7. Produce with methods that allow for the development of people.
Just in time production (JIT)
Just in time is a pull system of production, so actual orders provide a signal for
when a product should be manufactured. Demand-pull enables a firm to produce only
what is required, in the correct quantity and at the correct time.
This means that stock levels of raw materials, components, work in progress and
finished goods can be kept to a minimum. This requires a carefully planned
scheduling and flow of resources through the production process. Modern
manufacturing firms use sophisticated production scheduling software to plan
production for each period of time, which includes ordering the correct stock.
Information is exchanged with suppliers and customers through EDI (Electronic Data
Interchange) to help ensure that every detail is correct.
Supplies are delivered right to the production line only when they are needed. For
example, a car manufacturing plant might receive exactly the right number and type
of tyres for one days production, and the supplier would be expected to deliver them
to the correct loading bay on the production line within a very narrow time slot.
Advantages of JIT
1. Lower stock holding means a reduction in storage space which saves rent and
insurance costs
2. As stock is only obtained when it is needed, less working capital is tied up in stock
3. There is less likelihood of stock perishing, becoming obsolete or out of date
-
8/2/2019 Pritika New
5/25
4. Avoids the build-up of unsold finished product that can occur with sudden changes
in demand
5. Less time is spent on checking and re-working the product of others as the
emphasis is on getting the work right first time
Disadvantages of JIT
1. There is little room for mistakes as minimal stock is kept for re-working faulty
product.
2. Production is very reliant on suppliers and if stock is not delivered on time, the
whole production schedule can be delayed
3. There is no spare finished product available to meet unexpected orders, because all
product is made to meet actual ordershowever, JIT is a very responsive method of
production the purposes of:
Reducing Cost Improving Quality Improving Performance
Improving Delivery Adding Flexibility Increase innovativeness
JIT and Elimination of Waste:
JIT usually indentifies seven prominent types of waste to be eliminated:
1. Waste from Overproduction
2. Waste of waiting/idle time
3. Transportation Waste
4. Inventory Waste
5. Processing Waste
6. Waste of Motion
7. Waste from Product Defects
-
8/2/2019 Pritika New
6/25
List of Companies that use just in time (JIT):
Harley Davidson Toyota Motor Company General Motors Ford Motor Company Manufacturing Magic Hawthorne Management Consulting Strategy Manufacturing Inc.
Benefits of JIT to the companies.
The main benefits of JIT are listed below.
1. Set up times are significantly reduced in the warehouse which will allow the
company to improve their bottom line to look more efficient and focus time spend on
other areas.
2. The flows of goods from warehouse to shelves are improved. Having employees
focused on specific areas of the system will allow them to process goods faster instead
of having them vulnerable to fatigue from doing too many jobs at once and simplifies
the tasks at hand.
3. Employees who possess multi-skills are utilised more efficiently. This will allow
companies to use workers in situations where they are needed when there is a shortage
of workers and a high demand for a particular product.
4. Better consistency of scheduling and consistency of employee work hours are
possible. This can save the company money by not having to pay workers for a job
not completed or could have them focus on other jobs around the warehouse that
would not necessarily be done on a normal day.
5. Increased emphasis on supplier relationships is achieved. No company wants a
break in their inventory system that would create a shortage of supplies while not
having inventory sit on shelves.
6. Supplies continue around the clock keeping workers productive and businesses
focused on turnover. Having management focused on meeting deadlines will make
-
8/2/2019 Pritika New
7/25
employees work hard to meet the company goals to see benefits in terms of job
satisfaction, promotion or even higher pay.
Classic JIT diagram
The classic JIT diagram is as below. There the company (the boat) floats on a sea of
inventory, lurking beneath the sea are the rocks, the problems that are hidden by the
sea of inventory.
|
--|--
|
---------------
\ /
========\ Company /============ Sea of inventory
\---------/
x
xxx xxxx
xxxxx xxxxxx Rocks - the problems hidden
xxxxxxxxxxxxxxxx by the sea of inventory
If we reduce the inventory level then the rocks become exposed, as below.
|
--|--
|
--------------- x
\ / xxx xxxx
========\ Company /====xxxxx===xxxxxx========
\---------/ xxxxxxxxxxxxxxxx
-
8/2/2019 Pritika New
8/25
Now the company can see the rocks (problems) and hopefully solve them before it
runs aground!
One plan to expose the problems is simply to:
make a large amount of finished goods stock to keep the customers supplied try running the production system with less inventory to expose problems revert to the original levels of inventory until you have had time to fix the
problems you exposed
repeat the above - hence continuous improvement
Suppliers
Suppliers can be crucial to JIT success
Supplier gets:
long-term, guaranteed, contract a good price steady demand minimal paperwork (e.g. use electronic means to order - such as email or Web
or electronic data interchange, EDI)
In return the supplier agrees to
quality components (e.g. zero defects) guaranteed delivery times a "partnership" with its customer contingency plans to cope with disruptions, common disruptions might be:
o the effect of bad weathero a truck drivers strike blocking roads/portso a flu outbreak reducing the supplier's workforce
Supplier selection criteria:
close to production plant (else potential transportation delays)
-
8/2/2019 Pritika New
9/25
good industrial relations ("involvement", "value", "dignity", "ownership"), nostrike deals
you believe that the supplier can met their promises with respect to the list offactors given above that that they are agreeing to
With suppliers satisfying these criteria you can reduce the total number of suppliers,
indeed it seems logical so to do. If you had five suppliers meeting all these criteria
why do you need five? Obviously you might decide to have more than one supplier
for safety reasons. Even the best run supplier can suffer a factory fire or an
earthquake, but probably no more than two or three suppliers.
JIT implementation design
Based on a diagram modeled after the one used by Hewlett-Packards Boise plant to
accomplish its JIT program.
1) F Design Flow Process
F Redesign /relay out flow L Reduce lot sizes O Link operation W Balance work station capaity M Preventive maintenance S Reduce setup times
2) Q Total Quality Control
I automatice inspection M Quality measures
M Fail safe methods W Workers participations
3) S Stabilize Schedule
S Level schedule W Establish freeze window UC Under utilize capacity
-
8/2/2019 Pritika New
10/25
4) K Kandan pull system
D Demand pull B Back flush L Reduce lot size
5) V Work with Vendors
L Reduce lead time D Frequent deliveries U Project usage requirement Q Quality expectation
6) I Further Reduce Inventory in Other Areas
S Store T Transit C Implement carrousel to reduce motion waste C Implement conveyor belts to reduce motion waste
7) P Improve Product Design
P Standare production configuration P Standardize and reduce the no. Of parts P Process design with product design Q Quality expectations
Goal of Just in Time
According to Cheng in Just-In-Time Manufacturing An Introduction, he explains
the ideas of Suzaki for the objectives of JIT. There are three main objectives:
1. Increasing the organizations ability to compete with others and remain competitive
over the long run. The competitiveness of the firms is increased by the use of JIT
manufacturing process as they can develop a more optimal process for their firms.
2. Increasing efficiency within the production process. Efficiency is obtained through
the increase of productivity and decrease of cost.
3. Reducing wasted materials, time and effort. It can help to reduce the costs.
Other short-term and long-term objectives are:
-
8/2/2019 Pritika New
11/25
1. Identify and response to consumers needs. Customers needs and wants seem to be
the major focus for business now, this objective will help the firm on what is
demanded from customers, and what is required of production.
2. Optimal quality/cost relationship. The organization should focus on zero-defect
production process. Although it seems to be unrealistic, in the long run, it will
eliminate a huge amount of resources and effort in inspecting, reworking and the
production of defected goods.
3. Reduce unwanted wastes. Wastes that do not add value to the products itself should
be eliminated.
4. Develop a reliable relationship between the suppliers. A good and long-term
relationship between organization and its suppliers helps to manage a more efficient
process in inventory management, material management and delivery system. It will
also assure that the supply is stable and available when needed.
5. Plant design for maximizing efficiency. The design of plant is essential in terms of
manufacturing efficiency and utility of resources.
6. Adopt the work ethnic of Japanese workers for continuous improvement. Commit a
long-term continuous improvement throughout the organization. It will help the
organization to remain competitive in the long run.
Limitation of Just in Time
Regardless of the great benefits of JIT, it has its limitation, JIT has the following
major limitations:
1. Culture Differences The organizational cultures vary from firm to firm. There are
some cultures that tie to JIT success but it is difficult for an organization to change its
cultures within a short time.
Traditional Approach The traditional approach in manufacturing is to store up a
large amount of inventory in the means of backing up during bad time. Those
-
8/2/2019 Pritika New
12/25
companies rely on safety stocks may have a problem with the use of JIT.
Difference in implementation of JIT Because JIT was originally established in
Japanese, it is somehow different for implementing in western countries. The benefits
may vary.
Loss of individual autonomy This is mainly due to the shorter cycle times which
adds pressures and stress on the workers.
Loss of team autonomy This is the result of decreasing buffer inventories which lead
to a lower flexibility of the workers to solve problem individually.
Loss of method autonomy It means the workers must act some way when problems
occur, this does not allow them to have their own method to solve a problem.
JIT success is varied from industry to industry Some industries are benefit more
from JIT while others do not.
Resistance to change JIT involves a change throughout the whole organization, but
human nature resists to change. The most common resistance are emotional resistance
and rational resistance. Emotional resistance are those psychological feeling which
hinder performance such as anxiety. Rational resistance is the deficient of the needed
information for the workers to perform the job well.
Relationship between management and employees is important A mutual trust must
be built between management and employees in order to have effective decision
making.
Employee commitment Employees must commit to JIT, to enhance the quality as
their ultimate goal, and to see JIT as a way to compete rather than method used by
managers to increase their workload.
Production level JIT works best for medium to high range of production volume.
Employee skill JIT requires workers to be multi-skilled and flexible to change.
-
8/2/2019 Pritika New
13/25
Compensation Compensation should be set on time-based wages. This allow the
workers to concentrate on building what the customers wants.
Effect of Just In Time
Effect of Just-In-Time Purchasing Relationships on Organizational Design,
Purchasing Department Configuration, and Firm Performance
Just-in-time purchasing requires close relationship and co-operation on product
development and specification(product and information flow). It also involves joint
product design, extensive verification of supplier quality and shared production plan.
Three questions are addressed in this articles:
1. Is JIT purchasing associated with overall organizational design?
2. Is JIT purchasing associated with the configuration of purchasing?
3. Is JIT purchasing associated with performance?
To answer these questions, we have to first look at the factors that related to each of
the question. In consideration of overall organizational design, four different aspects
are discussed: formalization, decentralization, integration and specialization.
Formalization refers to formal internal performance control, formal benchmark
control and the strategic formalization of the purchasing function. It is found that themore JIT purchasing, the more internal and benchmark control are implemented. The
reasons for that are 1) JIT represents the exact process management, so more
performance information is needed to ensure that the remaining inventory meets the
specification. 2) JIT provides feedback which are essential to the succeed of JIT
implementation. And also, with the increase of JIT purchasing, a written statement of
shared vision(goal) of the firm is needed.
-
8/2/2019 Pritika New
14/25
Decentralization consists of line-operating decision and scheduling. JIT purchasing is
related to decentralized decision-making because a higher employees involvment will
result in higher performance. JIT purchasing is positively related to line-operating and
negatively related to scheduling.
Integration is the lateral communication. While there are more JIT purchasing, it is
very important to have a stable and good communication among departments within a
firm. Thus, JIT is positively related to integration.
Specialization focuses on division of labor. As more JIT purchasing, more labor is
needed to perform a faster production schedule. So, it is positively related to JIT. It is
very obvious that JIT purchasing is associated with overall organizational design.
To address the second question, we have to look into two aspects. They are the
number of layers for the purchasing function and the span of control of the senior
purchasing executive. The authors found out that JIT purchasing is negatively related
to the number of layers for the purchasing function and positively related to the senior
purchasing executives span of control.
For the third question - Is JIT purchasing associated with performance? JIT is
expected to be related with efficiency, financial performance and market performance.
And it is found out that JIT is negatively related to weeks of inbound inventory,
positively related to financial performance and market performance.
From this study, two managerial implications can be drawn. First, implementing JIT
exchange with suppliers. The relationship between buyer and seller is now toward
relational exchange as the JIT purchasing is more frequently used. Second, JIT
purchasing correlates with performance.
There are several importance tools for total quality management control:
1. relations diagram
2. Affinity diagram
3. Systematic diagram ( Tree diagram)
-
8/2/2019 Pritika New
15/25
4. Matrix diagram
5. Matrix data analysis
6. Process derision program chart
7. Arrow diagram
From seven tools, it help Japanese product quality to meet following total quality
management: The ability to eliminate defective products
The ability to improve productivity
The ability to complete tasks on time
The ability to increase product value-driven
The ability to completely eliminate waste
The ability to reduce lead time and inventory cost
Just in Time Inventory and Productive Management
Introduction:
Generally speaking, most of the company and factories must manage the inventory
material efficiently and effectively. Therefore, reducing levels of inventory stock in
company and factory is an internal and external matter. In terms of supply and
demands management, the Just-In-Time (Inventory Management) are linked
strategically and operationally. Take Japan for an example. Japan has encouraged the
adoption of just-in-time methods and quality management methods. That is the reason
why Japan can do a good job on economic performance. As to Technological
advances, it also play an important role on inventory management.
Essential Aspects inventory Management influence on Just in Time
Lessons have been learnt from Japanese methods where substantial efficiencies are
gained from frequent deliveries of small quantities to meet immediate demands. This
-
8/2/2019 Pritika New
16/25
compares with methods of stock control such as the economic inventory management
approach.
Reduction inventory in supply chains
Reduce transit time
Reduce manufacture cost
Increase management efficiency and effective
Reliable delivery
Short distances between client and server
Consistent quality so that server performance and throughput is unaffected
Just in Time-----Manufacturing
(1) Introduction
Just in Time---manufacturing is a systems method to develop and operate a factory
system. It is mainly basis on the total Decrease of waste. As you know, many people
think JIT is not a new knowledge field. As a matter of fact, it has been part and plays
an important role of the Japanese manufacturing industry adopted method for a long
time . It requires all the materials such as equipment, human resources, and
management skills are made available only in the amount required and at the time
required to do the job. It is based on producing only the necessary units in the
necessary quantities at the necessary time by bringing production rates exactly in linewith market demand. Generally speaking, JIT means making what the market wants.
JIT has been found to be so effective that it increases productivity, work performance
and product quality. Whats even more, it plays a vital role to increase productivity
and decrease the total cost of manufacturing production.
(2) Planning for JIT
-
8/2/2019 Pritika New
17/25
Since each manufacturing process is different, it is up to the individual company to
determine the degree of appropriateness and the final application of JIT. However, it
is very important to define the plan and objectives before setting up a JIT
manufacturing system. It is impossible to establish a new JIT system that can be used
successfully without change. Therefore, we should take serious consideration to make
a plan for Just-In-Time, which will benefit to our factory performance.
3) Defining the Planning
JIT manufacturing system requires an understanding of the objectives of JIT, and
objectives of the JIT system. After the objectives are set up for the manufacturing, the
process of planning becomes one of determining what is required to meet thoseobjectives. The goal of a JIT approach is to develop a system that allows a factory to
have only the materials equipment and people by hand required doing the some plan.
T o achieve this goal, we should have equipped with at least five fundamental plan:
a) Integrating and optimizing every step of the manufacturing process
b) Reducing manufacturing cost
c) Producing product on demand
d) Developing manufacturing flexibility
e) Produce quality product to maintain commitments and links made between
Customers and Suppliers
We also should keep in mind that achieving these obtaining targets do not
automatically make a company a JIT manufacturer. On the contrary, it will lead to
achieve even one of these objectives will prevent a manufacturer from establishing a
successful JIT system. According to Common Wealth on May, 1996 report, it said
that A company cannot decide to implement JIT; they must earn the right to use JIT
by revising their quality for system."
(4) Reducing Manufacturing Cost
-
8/2/2019 Pritika New
18/25
If we can design products that it will speed up and decrease manufacturing processes.
Gradually, it will helps us to reduce the cost of manufacturing and building the
product to specifications benefit. One aspect in designing products for manufacture
ability is the need to set up a good boss and employee relationship. At least, this is to
cultivate and procure the resources of the production experts, and the line employees
to develop cost saving solutions. Participatory quality programs utilize employee
knowledge about their job functions and review the department performance. It will,
finally, encourage with rewards for suggested total cost saving.
(5) Manufacturing Flexibility
According to China time report on August 1996. "Manufacturing flexibility is theability to start new projects or the rate at which the production mix can be adjusted to
meet customer demand." Planning for manufacturing flexibility requires the
understanding of the elements in the manufacturing process and understanding
elements in the process that restrict flexibility and improving on these areas. The
unique feature of Just-In-Time is the modification from between pull and push
systems. The main idea behind these approaches are that "work should not be pushed
on to the next worker until that worker is ready for it." (Hauser, J.R.) As a result,
manufacturing flexibility requires production managers to consider the some
important factors, such as supplier lead time, production process time, process setup
time and so forth.
6) Keep in touch between customers and suppliers
For factory main commitment to achieving the internal structures, both customer and
supplier are also playing a vital role to support JIT manufacturing. Because it is theprimary requirement for developing the JIT system, each other can establish trust and
honest between the supplier and the customer which is a must, since every Just-in-
Time operation depends on it. Supposed, finally, it leads to failure to keep the
commitments each other. Finally, it will be result to a serious form of breakdown
manufacturing systems. Therefore, we should pay attention to this kind of serious call.
Never be ignorant of this commitment. If we can make use of Just-In-Time
(manufacturing approaches), it, eventually, will attain those goal, which are the
fundamental concept of producing product only as needed or on demand.
-
8/2/2019 Pritika New
19/25
Example:
Toyota manufacturing processes route the product around the plant to various work
centers where work is staged to be processed. Implementing manufacturing cells
typically increases net income dramatically and reduces cycle time over 50%. The
cost of design and implementation is usually recovered within the first year from
inventory savings. In this paper, we present the benefits of bringing the processes to
the product and discuss the value of simulation as a tool to design and predict cell
performance prior to implementation; therefore, reducing financial and technical risk
to the company.
On September 10, 1997, Mr. Hoskins presented on "Improve Profits and ReduceCycle Time with Manufacturing Cells and Simulation" for the National Technology
University series on Kanban just-In-Time Manufacturing of this series. On October 27
- 28, 1996 Jerry Hoskins, President presented a paper titled "Developing a Lean
Implementation Roadmap" at the SME Kanban Manufacturing Conference in
Dearborn, Michigan. The intent of this paper is to provide information to companies
on where to start with a Kanban implementation based on where one is currently
manufacturing operation. His theory help our many manufactures implement all the
elements of Kanban Manufacturing directed at elimination of manufacturing waste as
defined by the Toyota Production System. These systems are more flexible,
responsive, and profitable than traditional manufacturing systems. And, its theory also
help our many participate determine where best to start with a Kanban
implementation which usually involves an assessment of current operations. Once
plan is developed we design the system to be implemented which may involve layout,
cells, JIT, process technology, and process simulation.
Elements of Just in Time
According to Cheng, the basic elements of JIT manufacturing are:
People Involvement
Plants
System
-
8/2/2019 Pritika New
20/25
People Involvement
Maintaining a good support and agreement from people involved in production. This
is not only reduce the time and effort in implementation of JIT, but also minimize the
chance of creating implementation problem. (Cheng, 6) The attempt to maximize
peoples involvement may carry through the introduction of quality circle and total
involvement concept. (Cheng, 7)
Manufacturers can gain support from 4 sources.
1. Stockholders and owners of the company - should maintain a good long-term
relationship among them.
2. Labor organization - all labors should be well-informed about the goals of JIT, this
is crucial in gaining support from the them.
3. Management support - support from all level of management. The ideas of
continuous improvement should spread all over the factory, managers and all shop-
floor labor.
4. Government support - government can show their support by extending tax and
other financial help. This can enhance the motivation, and also help in financing the
implementation of JIT.
Plants
Certain requirements are needed to implement JIT, there are:
1. Plant layout - the plant layout is mainly focus on maximizing working flexibility. It
requires the use of "multi-function workers".
2. Demand pull production - it means to produce when the order is received. This can
manage the quantity and time more appropriately.
3. Kanban - a Japanese term for card or tag. Special inventory and process
-
8/2/2019 Pritika New
21/25
information are written on the card. This helps tying and linking the process more
efficiently.
4. Self-inspection - it is carried out by the workers at catch mistakes immediately.
5. Continuous improvement - this concept should be adopted by every members in the
organization in order to carry out JIT. This is the most important concept of JIT. This
can allow an organization to improve its productivity, service, operation and even
customer satisfaction in an on-going basis.
System
This refers to the technology and process that combines the different processes and
activities together. Two major types are MRP (Material Requirement Planning) and
MRP II (Manufacturing Resource Planning). (Cheng, 8)
MRP is a computer-based, bottom-up manufacturing approach. This involves two
plans, production plan and master production schedule. Production plan involves the
management and planning of resources through the available capacity. Master
production schedule involves what products to be produced in what time. (Cheng, 8)
MRP II is mainly involved the management or planning of financial resources in
order to carry out the operation.
The above three factors formed the element of JIT.
JIT approaches
Three main approaches are possible:
1. Reducing manufacturing and administrative cycle times
2. Reducing all waste
3. Reducing the pulled flow breakdowns
Cycle time reduction
-
8/2/2019 Pritika New
22/25
The cycle time represents the time between the customer demand and its final
delivery:
1. Manufacturing cycle time includes the machining, transportation, inspection and
warehousing. Classical tools are used to reduce these cycle times such as SMED,
TPM, 5S
2. Administrative cycles are less visible since they more occur in the background.
They include order entries, purchase entries & follow-up, payments, credit notes
Depending on industries, there can be up to 90% waiting time and 10% value added
time!
Waste reduction
The wastes encompass all operations not having any value added on a given product.
Shigeo Shingo from Toyota has classified them among 7 root causes:
1. Over-production: to be sure to get the right component quantity, we produce
more!
2. Queues or Waiting time: Products dont move as produced to early
3. Transports: No value added and can be expensive (e.g. factory transfer,)
4. Processes: If not well adapted to the operation to perform, there can be a waste of
time
5. Movements: Useless movements in a shopfloor or around a line.
6. Non-Quality: Defective products are pure financial loss!
7. Inventory: Overstocking is usually seen when disruptions occurred during the
manufacturing cycle, when a machine is down too often for instance or when
absenteeism is always over predicted.
Japanese people use to say that the inventories are made to tackle unsolved problemsin order to maintain the throughput rate.
So the method consists in reducing slowly the inventories in order to continuously
solve the issues causing problems:
-
8/2/2019 Pritika New
23/25
Flow breakdowns
This approach consists in identifying all the flow breakdown causes in order to
eliminate them.
The main objective is to maintain a high throughputs rate in order to quickly assemble
or produce the products to get faster sales revenues.
The causes could be classified as following:
Random breakdowns:
o Waiting timeso Missing part or componento Machine breakdowno Absenteeism
o Rework
-
8/2/2019 Pritika New
24/25
o Waiting for decision (after inspection) Operation breakdowns:
o Inspectiono Transit (between shopfloors or to warehouse)o Handling / Warehousing
JIT change management scope
The JIT is a full process that impacting all factory main functions, from sales to
purchasing troughout the supply chain:
Sales: From maximizing turnover at all cost to maximizing margins. Salespeople should change their habits to avoid big ordering waves disturbing the
manufacturing line, by smoothing orders through the year and get yearly
discount instead of individual order discounts. New metrics for sales
performance are hence required.
Suppliers: There are fewer suppliers but they are considered as partners with
long term contracts in order to get a stable supply plan and reduce the
shortage. Hence long term forecasts are issued so that they can plan
accordingly. Supplier Schedules are used, replacing traditional purchase
orders, and reception inspection is skipped or simplified for selected suppliers
allowing direct delivery to the manufacturing line.
Distribution: It can represent up to 40% of the cost paid by the customer.
Distribution is optimized by increasing delivery frequencies to reduce
inventory levels and reducing the number of warehouses.
-
8/2/2019 Pritika New
25/25
Engineering: Products are standardized in order to reduce the number of
components and lower the safety stocks. Then products are simplified as much
as possible: less bill of material levels, simpler routings, fewer operations but
productivity should increase by reducing the value added times.
Manufacturing lines: Machines are grouped by products family not by their
functions anymore. The raw material and components are stored on the line
itself, replacing a central warehouse (and high inventory). Preventive
maintenance is done to reduce the number of machine breakdowns, flexibility
and reduced exchange die are searched, non-quality is avoided and machining
setup is simplified.
Human Resources: The workforce is back in the middle of the productionprocess. Continuous improvement is performed at all levels every day. The
work environment is optimized, less noisy, clean and safety is improved.
Workers are taking decisions over the lines in order to improve the
manufacturing layout and the line efficiency. Performance is now measured
accordingly: team performance instead of individual, manufacturing schedule
adherence per product rather than total quantity produced of all items,
Conclusion:
The JIT is rather a philosophy or a concept than a simple method. All departments are
involved to change from traditional manufacturing to lean production. It is a long
process that needs to be followed over a decade to get fruitful results
top related