A Case Study on Just in Time (JIT)

IJSRD - International Journal for Scientific Research & Development| Vol. 2, Issue 08, 2014 | ISSN (online): 2321-0613
All rights reserved by www.ijsrd.com 330
A Case Study on Just in Time (JIT)
Swapnil S. Dange1
Prof. Prashant N. Shende2
Chetan S. Sethia3
1,3
M. Tech Student 2
Assistance Professor
1,2,3
Department of Mechanical Engineering
1,2,3
Yeshwantrao Chavan College of Engineering, Nagpur (An Autonomous Institution Affiliated to
Rashtrasant Tukadoji Maharaj Nagpur University, Nagpur)
Abstract— Productivity improvement is the one of the basic
need of every manufacturing industry, so that Just in Time
(JIT) is one of the quality tools that are help to improve the
productivity. Just in Time (JIT) has been very popular
strategy partly because of its success in Japanese
manufacturing, Automobile industries. Analysis of wastages
is one of the needs of every industry, so we are using the
value mapping analysis to check each value-added and non-
value-added activity. Just in Time (JIT) is a system that
focuses on inventory control, set up time reduction, waste
reduction and continuous improvement to achieve
operational excellence. In this paper a single case study is
doing in the manufacturing company (Towers making). The
main objective of this paper to checking each and every
activity to achieve the manufacturing time is less than
customer order time. Take a pad and pencil and go out on
the shop floor. Pick a product and follow it through the
entire manufacturing process from raw materials to
shipping. Note every activity performed on the product. Do
not get a routing slip to see how the process is supposed to
go, but accurately record the process including delays,
transportation, inspection, storage, etc. After recording time
to calculate Available operating time, performance factor,
quality rate and overall equipment efficiency. After
calculating overall equipment efficiency to compare with
international standard and get suggestions to the case
company.
Key words: Just in Time (JIT), Value-added and non-value-
added activity, Inventory control, Time reductio.
I. INTRODUCTION
Why Just-In-Time manufacturing when there are dozens of
other manufacturing philosophies from which a company
may choose? Just-In-Time (JIT) manufacturing distances
itself from the competition because no large capital outlays
are required. Other methods promote complexity, large
overheads, automation, and other "state-of-the-art"
technologies, while JIT advocates simplifying and
streamlining the existing manufacturing process. Since
World War II, traditional American companies have
developed a way of doing business that entails top
management planning, re-planning, and more planning.
Although some planning is good, it ultimately adds no value
to the end product. Customers want quality products at
competitive prices - they couldn't care less how much
planning was required to get that product to them. By
implementing JIT, much of the planning disappears and a
large portion of the remaining planning is entrusted to the
shop floor personnel.
The purpose of this text is to introduce basic JIT
concepts and assure you that JIT can work in your company.
The transition to JIT often is not easy, but it is almost
always rewarding. All employees in the company - from top
management to direct labour - must have a clear
understanding of the benefits that JIT offers to them and to
their company. JIT is not a cure-all for every manufacturing
problem. But, if implemented properly, JIT is a no-cost or
low-cost method for improving your manufacturing process.
JIT was invented by Taiichi Ohno of Toyota shortly after
World War II. Ohno's system was designed to handle large
or small volumes of a variety of parts. Many people are
intimidated by JIT because of its association with Japan. If
these people take a broader look at JIT, they will see that it
is nothing more than good, common sense manufacturing.
Ohno and his associates came to America to study our
manufacturing processes. They determined that our system
was much like the system that Japanese companies were
using, but Japanese companies could not afford waste in
their systems due to the devastation to their economy caused
by World War II. While in America, Ohno learned much
about America's culture. One of his discoveries has
transformed the world's perspective on manufacturing.
The roots of JIT system can probably be traced to
Japanese manufacturing industries. Japan has inherent
limitation of lack of space and lack of natural resources.
Japanese have developed an aversion towards all kinds of
wastes. They view scrap and rework as waste and hence
strive for perfect quality. They strongly believe that
inventory storage wastes space and results in locking up of
valuable material and capital. Anything that does not
contribute value to the product is viewed as waste. Thus, it
is quite natural for the JIT philosophy to develop in Japan.
Apart from eliminating wastes JIT has another important
feature utilizing the full capability of the worker. Workers in
JIT system are charged with responsibility for producing
quality parts Just in Time to support the next production
process. The objective of JIT system is to improve profits
and return on investment through cost reduction, inventory
reduction and quality improvement. Involvement of workers
and elimination of waste are the means of achieving these
objectives [18]
Legend has it that Ohno got the idea for his
manufacturing system from America's supermarket system.
Ohno learned the kanban (pull) system from our
supermarket system in which customers pulled items from
the shelves to fill their shopping carts, thereby creating an
empty space on the shelf. The empty space is a signal for the
stocker to replace that item. If an item was not bought that
day, there was no need to replace it. When item quantities
become low, that is the signal for the stockers to order more
goods from their suppliers. Customers are content to take
just what they need, because they know that the goods will
be there the next time they need them.
To apply this concept to manufacturing, Ohno
devised a system whereby the usage of parts is determined
by production rates. Materials are pulled through the plant
by usage or consumption of the parts in final assembly. To
obtain maximum results, Ohno decided to move the

(IJSRD/Vol. 2/Issue 08/2014/075)
machines closer together and form manufacturing cells. The
JIT system continued to evolve, with the central thrust being
the elimination of waste. Ohno's system has become a
totally flexible system in which production rates are
determined by the end user rather than the producer.
II. LITERATURE REVIEW
The main focuses on product quality, product delivery time
and cost of product. The objective of this paper is to
increase the productivity and quality of work by
implementing the JIT [1]. This author take the semi
structured interviews were organized and thus relevant data
can be collected. The conclusion of this research indicates
that JIT system can lead to many advantages to the company
[2]. The fundamental focus of JIT is the systematic
elimination of non-value added activity and waste for the
production process [3]. The flux used in submerged arc
welding after use generates wastages of flux i.e. slag. It is
generally thrown away as waste after use. So this slag
collected and mixed with some additives and reused. Waste
reduction is important issue in today‟s context. The main
objective of the waste reduction is to minimize waste while
the resource management aims to maximize the utilization
of resources [4]. This author focus on Buffer stock removal,
cellular manufacturing, group technology, layout
improvement, set up time reduction, worker motivation,
W.I.P. reduction. This paper contributes to the Just in Time
(JIT) literature by providing a better understanding of why
firms consider JIT adoption to be beneficial [5]. This paper
stressed on long term benefits resulting from waste
elimination, and continuous improvements to systems,
programs, products, and people. This paper presents the
concepts, implementation strategies and benefits of Just in
Time (JIT) based quality management in detail [6]. The
main focuses on producer consumer relationship separated
by a Buffer, to a simultaneity constraint. JIT system focuses
on waste reduction and continuous improvement to achieve
operational excellence [7]. This is based on the application
of activity based management. To check each activity and
reduces the non-value adding activity [8].
There is reasonable consensus among researchers
that Just in Time (JIT) is a philosophy of continuous
improvement in which non-value-adding activities are
identified and removed in order to reduce cost, improve
product quality, improve performance, improve delivery,
add manufacturing flexibility and stimulate innovation in
workplace [11, 12, and 13]. When the JIT principles are
implemented successfully across many parts of an
organization, a significant competitive advantage can be
enjoyed. Enhanced efficiency from waste reduction in order
taking, purchasing, operation, distribution, sales and
accounting [14, 15]. Operationally, JIT production requires
that waste be identified and eliminated in the following
areas: waste from overproduction, waste created by waiting
or idle time, waste of motion, transportation waste,
processing waste and waste from product defects [16, 17].
III. ELEMENTS OF JUST IN TIME (JIT)
 Buffer stock removal [1,6,8]
 Cellular manufacturing [6]
 Continuous quality improvement [6,3]
 Kanban system [5,6,8,10]
 Kaizen [6,7,8]
 Layout improvement [1,6,8]
 Total productive maintenance [1,6]
 Work in process (WIP) reduction [1,6,8]
 Preventive maintenance [1,6]
 Set up time reduction [1,6,8]
 Group technology [6]
 Multifunctional workers [4,6]
 Small lot size [6]
IV. BENEFITS OF JUST IN TIME (JIT)
 Reduced labour cost [1,6,8]
 Reduced number of parts [6,812]
 Reduced scrap and rework [6,8,9]
 Reduced material handling [5,6,16]
 Reduced set cost [6,8]
 Increased communication [2,3,4,6,7,8,9]
 Increased efficiency and responsiveness [1,6,8]
 Increased resource utilization [6]
 Increased productivity [1,6,8]
 Increased team work [4,6,15]
 Increased innovation [6]
 Improved worker motivation [6,12,13,14]
 Integrate different manufacturing activity [6,8,10]
 Increased product quality [1 to 16]
V. CASE STUDY
This part provides case study information that will be
referred to as „ABC Limited‟ and its introduction to JIT
manufacturing. This case study is part of a larger study that
focused on manufacturing strategy. The case study was
conducted over 15 days and calculates the efficiency of 5
days. Data was collected taking semi-structured interviews
conducted in case company, checking activity during plant
visits, and production and marketing reports.
XYZ Enterprises has been promoted by the family
or Mr. ABC in the year 1993 and is engaged in the activity
of manufacturing Line Towers, Microwave Towers, Sub
Station Structure and Railway Electrification. It has two
manufacturing facilities, both situated in the same Industrial
area. XYZ Ltd. factory‟s raw material storage is spread over
the vast area about 400 meters square. All the raw material
is unloaded by trucks here in this storage, the storage have
its own toll to weight the steel angle bars and other products
while either coming in the factory or while outgoing. All the
necessary paper work is done and the documents are safely
placed in order. There is a supervisor and some helping staff
that works in the storage and takes care about all the
necessary jobs in the storage.
 Unit 1- Has hot dip Galvanizing facility with both
sizes of 7000 mm long
 Unit 2- Has the Fabrication facility and galvanizing
facility with a bath size of 10000 mm long.
 Unit 3- Has the Fabrication facility only.

A. Process carried out:- The following are the process
carried out:
Fig. 1 process carried out in the industry
B. Checking each and every activity in industry:-
To identify waste in your company, a value-added analysis
should be performed. We must always be aware that any
activity that does not add value to a product is waste. There
are specific methods for performing a value-added analysis
but we will use a simplified approach for our purposes. Take
a pad and pencil and go out on the shop floor. Pick a product
and follow it through the entire manufacturing process from
raw materials to shipping. Note every activity performed on
the product. Do not get a routing slip to see how the process
is supposed to go, but accurately record the process
including delays, transportation, inspection, storage, etc.
Following table I show the value-added and non-value-
added activity with time in minute,
Sr.
No.
Name of Activity
Value
Added Time
(min)
Non-value
Added Time
(min)
1
Place the raw
material in
warehouse
5.30
2
Place it for more
time
30
3
Raw material input
for cutting
5
4
Keep the plates
outside separately
4.37
5
Move them by
crane
3.48
6
Pick and place on
CNC machine
2.10
7
At same time of
CNC machine;
punching, stamping
and notching is
done
1
8
Keep the plates
outside separately
in store
10
9
Pick and place on
crane
0.30
10 Move by crane 2.50
11
Then put them on
manual notching
machine
0.45
12
Do the notching
operation
0.10
13
Move them by
crane
3.20
14
Pick and place on
finishing operation
7.35
15
Keep the plates
outside separately
in store
20
16
Move them by
crane
2.49
17
Place them on
manual and
automatic End
Milling machine
2
18
Do End Milling on
half job
12
19
Pickup the job and
put it again in
position reverse of
the previous
2.10
20
Again do
remaining half End
Milling
12
21 Store them outside 5
22 Move them by
pallet truck to
second shop
10
23 Put them on
Grinding machine
1.20
24 Do the grinding 10
26 Move by crane 6.28
27 Put on Hot
Bending and Cold
Bending machine
3
28 Do hot bending and
cold bending
30
29 Put them on crane
and move in
fabrication shop
5.39
30 Again some
punching is done
3.40
31 Then move them
by pallet truck to
galvanizing section
4.25
32 Galvanizing is
done
90
33 Check out the
thickness of
galvanized plate
0.30
34 Inspect them by
using tachometer
0.10
35 Then place on the
crane
1.5
36 Move them by
crane
6.35

37 Place them to
warehouse
2
38 Jobs are coloured
country wise
2.29
39 Store at warehouse 45
40 Shipping by trucks 15
Table 1
Table 1 showed us that 40 total activities take place before
the customer receives the part. Only 29 of these activities
add value, therefore all other activities must be considered
waste. Even though some of these wasteful activities are
absolutely necessary, they are still waste and should be
viewed as such. We will now streamline the manufacturing
process, using JIT techniques that will be discussed in-depth
later. Table II shows that non-value-added activities,
Sr.
No.
Name of Activity
Time
(min)
1 Place it for more time 30
2 Keep the plates outside separately 4.37
3
Keep the plates outside separately in
store
10
4
Keep the plates outside separately in
store
20
5 Do End Milling on half job 12
6
Pickup the job and put it again in
position reverse of the previous
2.10
7 Again do remaining half End Milling 12
10 Place it for more time 5.39
11 Keep the plates outside separately 45
Table 2
C. Calculating the OEE from table I and II:
Value Added = Total Process Time = 3.73 Hrs =223.8 min
Non Value Added =3.01 Hrs = 180.6 min
Total Time = Total Process Time + Non Value Added
= 223.8 + 180.6
= 404.4
D. Calculating For One Shift:-
1) Available Operating Time (AOT)
AOT = 1 Day * 1 Shift * 8Hrs
= 8 Hrs
= 7.5 Hrs (Take Half Hrs Allowances)
= 450 min
Availability Factor = Total Process Time =404.4 min
Availability = Valuable Operating Time / AOT
= 404.4 / 450
= 0.89
= 89%
Availability factor = 89%
2) Performance Factor (PF)
Designed Cycle Time = 6.41 Ton / Hrs
Output = 23.422 Ton
Performance rate = [(design cycle time*output) / operating
time]
= [((60 min / 6.41ton) * 23.422) / (404.4 * 60)
= 0.5421
= 54.21%
Performance factors = 54.21 %
3) Quality Factor (QF)
Scrap = 2%
Total Amount of Defect = 0.47 Ton
Production Input = 23.90 Ton
Quality rate = (production input – quality defects) /
(production input)
= (23.90 – 0.47) / (23.90)
= 0.98
= 98%
Quality Factor = 98%
E. The Overall equipment effectiveness:-
OEE = Availability*Performance rate*Quality rate
= 0.89*0.5421*0.98
= 0.47
= 47%
Therefore, the Overall equipment efficiency of plant is 47%.
It is very important to recognize that improving OEE is not
the only objective. The beauty of OEE is not that it gives
you one magic number; it‟s that it gives you three numbers,
which are all useful individually as your situation changes
from day to day. And it helps you visualize performance in
simple terms-a very practical simplification.
Following table III shows the calculation of OEE to
shift wise,
Table 3
OEE Company OEE world class
Availability 87.4 90%
Performance 57.07% 95%
Quality 98% 99%
Table 4

Fig. 2 Graph of AF, PR, and QF
VI. SUGGESTION
 By implementing the JIT we can eliminate the
waste and also reduces inventory problem.
 I observed that the in order time required for
transfer of component from one machine to another
machine is more so we can suggest to use conveyor
system to reduce the time.
 The time required after hot bending and cold
bending to transfer the component from plate shop
to again fabrication shop is more, so arrange the
hot bending and cold bending near or in the
fabrication shop.
 The performance factor is very less to affect
efficiency so reduces non value added activity so
the efficiency is increases.
 Using an in-line configuration it is most
appropriate for system in which the parts progress
from one work station to the next in a well- defined
sequence with no back flow.
VII. CONCLUSION
A manufacturing processes and the resource available for
producing towers have been studied. From the calculation it
is seen that Availability factor to be 87.4% the performance
rate 57.07% and the Quality rate is 98%, so the total
effectiveness should be 48.88%. This study indicates that
the company adopting JIT practices have experienced
considerable benefits in all of the measured areas: quality
improvement, time based responses, employee flexibility,
firm profitability, and inventory reduction. These study
results demonstrate that JIT implementation improves
competitive performance by lowering inventory levels and
reducing quality costs and non-value added activities.
For the future scope of JIT to capture more fully
the complementarities that exist amongst JIT
implementation and other organizational policies and
procedures, including the economic and environmental
context that influence both the choice of different
manufacturing strategies and their subsequent impact on
financial performance.
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[2] Bo Hou, Hing Kai Chan; Xiaojun Wang; “ A Case
Study of Just-In-Time System in the Chinese
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Congress on Engineering, 2011.
[3] S. P. Vendan, Sakthidhasan; “Reduction of
Wastages in Motor Manufacturing Company”;
JJMIE, 2010.
[4] Dalgobind Mahto; Anjani Kumar; “Novel Method
of Productivity Improvement and Waste Reduction
Through Recycling of Submerged Arc Welding
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[7] T. Karkoszka, J. Honorowicz; “Kaizen Philosophy
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[16]Cheng, Podolsky; “Just-in Time manufacturing-an
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in Time”; Operations Management Review, 1990.
[18]Martand Telsang; “Industrial Engineering And
Production Management”; Reference Book; S.
Chand Publication; First Edition 1998.
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A Case Study on Just in Time (JIT)

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