International Journal of Engineering Trends and Technology (IJETT) - Volume4Issue4- April 2013
IMPLEMENTATION OF TOTAL PRODUCTIVE MAINTENANCE IN INDUSTRY – A CASE
STUDY
P.Prakash1, S.Kumar2, T.Sakthieswaran2
1,2,3,4
B.E. Mechanical Engineering,
P.A.College of Engineering and Technology,
Pulliampatty Post,
Pollachi – 642 002, Coimbatore District, Tamil Nadu, India.
ABSTRACT
Total Productive maintenance (TPM) is an innovative approach which holds the potential for enhancing
efficiency of production facilities. TPM is a process that maximizes the productivity of equipment for its
entire life. It demands significant change of work culture and radical restructuring of work. It eliminates
breakdowns and promotes autonomous operator maintenance through day-to-day activities, which
involve the total workforce. It fosters an environment where improvement efforts in safety, quality, cost,
delivery and creativity are encouraged through the participation of all employees. It is a strategic
management initiative to increase capacity and end the vicious cycle of breakdown or reactive repairs
through the use of autonomous and predictive maintenance, as well as equipment modifications to
facilitate optimum machine availability, quality and performance. TPM will drive the operational
efficiency of a manufacturing environment and profitability of the organization. In our project we focus
on studying the existing methods for rescheduling Section Layout, implementing 5S Principles in the shop
floor, manufacturing systems management, and maintenance management and to improve the efficiency
of process with TPM implementation. 5s is an integral step in TPM. It focuses on developing stability and
standardization in the organization. It can provide benefits in areas from safety to quality. Time study and
motion study were performed to identify the existing problems, faults and defects and to develop the
knowledge on process handled in a small scale industry. It is then analyzed in detail and as a result
inefficiencies of the present methodology are identified. We concentrate on improving the robustness of
production process, improving utilization of labor forces, increasing equipment reliability and increasing
the profit of the organization by satisfying the customers with the products. The impact of changes made
as a consequence of implementing such improved methods was evaluated and benefits were discussed.
manufacturing process. The goal is to hold
1. INTRODUCTION
emergency and unscheduled maintenance to a
1.1. What is TPM?
Total Productive Maintenance (TPM) is a
minimum.
maintenance program which involves a newly
1.2 Implementation of TPM.
defined concept for maintaining plants and
To begin applying TPM concepts to plant
equipment. TPM is an innovative Japanese
maintenance activities, the entire work force
concept originated in 1951 when preventive
must first be convinced that upper level
maintenance was introduced in Japan. The goal
management is committed to the program. The
of the TPM program is to markedly increase
action teams are charged with the responsibility
production while, at the same time, increasing
of pinpointing problem areas, detailing a course
employee morale and job satisfaction. It can be
of corrective action, and initiating the corrective
considered as the medical science of machines.
process. Recognizing problems and initiating
TPM brings maintenance into focus as a
solutions may not come easily for some team
necessary and vitally important part of the
members. They will not have had experiences in
business. It is no longer regarded as a non-profit
other plants where they had opportunities to see
activity. Down time for maintenance is
how things could be done differently. In well run
scheduled as a part of the manufacturing day
TPM programs, team members often visit
and, in some cases, as an integral part of the
cooperating plants to observe and compare TPM
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methods, techniques, and to observe work in
progress. TPM stands for “Total Productive
Maintenance” and builds a close relationship
between Maintenance and Productivity, showing
how good care and up-keep of equipment will
result in higher productivity.
TPM is a
philosophy of continuous improvement that
creates a sense of ownership in the operator(s) of
each machine. One piece of equipment at the
time". The implementation consists of a series
of improvements determined basically by the
input that the operator gives to the team. The
improvements will correct the discrepancies and
restore any features that the machine might have
lost through the time. Other tasks will be
designed to make the machine more efficient,
safe and easy to operate. Many of the
improvements will include not only the machine
itself, but the area in which it is installed.
Our focus will be:
 Ease the operation
 Improve the Productivity
 Ease the maintainability
One of the most common causes of damage,
deterioration or even breakdown of the
equipment is contamination from diverse
sources. Dust, debris, water, oil spills or other
agents frequently cause equipment to deteriorate
and make it difficult to verify correct operation.
For this reason, an initial cleaning and follow-up
actions to prevent contaminants from getting to
the machine are important tasks that we perform
while going through TPM implementation.
We will also make the operators and supervisors
aware of the ease and comfort that a clean
machine represents. A clean machine not only
looks nice, but it is easy to inspect, maintain and
keep up. When the machine is clean, we can tell
if there are any new discrepancies, such as leaks,
loose wires, hoses, bolts, nuts, screws, etc. A
TPM’s piece of equipment is less likely to
breakdown and its reliability will meet the most
demanding expectations, limited only by the
capacity it was designed for.
It is an ongoing process of continued
improvement supported by all the team. The
members of the team should communicate with
each other on a regular basis to find out how the
process is going and to decide if new
improvements should be considered and, if
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feasible, scheduled.
Just like many of the changes, challenges and
improvements that we must undergo in these
competitive times, this one will make us face
some reluctance from the most apathetic people.
The benefits that this system generates for
employees and the company make it worth the
effort.
1.3 SCHEDULING
A decision-making function that plays an
important role in most manufacturing a
industries. Scheduling is the process of deciding
how to commit resources between a variety of
possible tasks. Project scheduling is concerned
with a set of activities that are subject to
precedence constraints, specifying which jobs
have to be completed before a given job is
allowed to start its processing. All activities
belong to a single (and typically large) project
that has to be completed in a minimum time.
Good scheduling often allows an organization to
conduct its operations with a minimum of
resources.
2. ABOUT THE WORK
In our project, we analysed and collected datas
from an industry. We were allotted a section
namely KTM section. There are totally eleven
machines in this section. On viewing the
existing layout of the section, we found this
section untidy. We then decided to modify the
existing layout of the section. After a detailed
examination we suggested a modified section
layout. The company also accepted to implement
our modified section layout. Then we decided to
improve the process schedule of two standard
components namely Lathe Bed and Saddle. We
performed time study for these two components.
Analyzing the time chart, problems were
identified. To overcome these problems we
rescheduled the process flow and gave
suggestions to minimize the process time. We
found the section unorganized and shop floor
with full of inventories making the movement
and flow process difficult. To make the section
neat and to be well organized, suggestion was
given to implement and follow the 5S principles.
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After
company’s
implemented.
approval
5S
were
3. LAYOUT OF KTM SECTION
3.1 Plant Layout
3.2 EXISTING LAYOUT
SECTION
3.3 PROBLEMS IN THE
LAYOUT
OF
THE
1. The area occupied by unwanted fixtures of
double column vertical milling machine can be
used for placing input/output materials.
2. Space behind HMC can be used for placing
the unused fixtures.
3. The place occupied by unwanted fixtures of
HMC can be used for placing input/output
materials.
EXISTING
1. Unwanted fixtures of double column vertical
milling machine which are not in
use must be replaced.
2. These fixtures occupy more space
3. Space behind HMC is occupied by unwanted
materials.
4. Fixtures of HMC which are not used must be
replaced
5. Materials stacked between machines makes
the process flow difficult and also
crosses the yellow line.
3.4 SUGGESTIONS FOR THE EXISTING
PROBLEMS IN THE LAYOUT
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3.5 MODIFIED LAYOUT OF THE
SECTION AFTER IMPLEMENTING THE
SUGGESTION
COMPONENT NAME : LATHE BED
OPERATION
: PROFILING
MACHINE NAME
: DOBULE COLUMN
VERTICEL MILLING
MODIFIED TIME CHART
COMPONENT NAME : LATHE BED
OPERATION
: PROFILING
MACHINE NAME
: DOBULE COLUMN
VERTICEL MILLING
RESULT

3.6 ADVANTAGES OF THE MODIFIED
LAYOUT
1. When unwanted materials are taken out the
shop floor will look neat and tidy.
2. Flow of process can be made easier.
3. Space occupied by unwanted fixtures can be
utilized for placing input and output materials.
TIME STUDY
It is a work measurement technique for
recording the times and recording the times and
rates of working for the elements of a specified
job carried out under specified conditions, and
for analyzing the data so as to obtain the time
necessary for carrying out the job at a defined
level of performance.
EXISTING TIME CHART FOR LATHE
BED
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To complete the operation for a job it
takes 84mints for an operator. Std. time
for same operation is 65mints.
 More time is consumed in setting and
cleaning. If the operator is trained to set
the job, he could set the job quickly.
2minutes can be reduced in this.
 If pneumatic cleaning is performed
another 30secs can be consumed.
 Another operator must be assigned to
look after the other machine.
5. OVERALL EQUIPMENT EFFICIENCY
Our goal is to increase equipment efficiency so
each piece of equipment can be operated to its
full potential and maintained at that level. To
maximize equipment efficiency, it is essential to
understand equipment problems and the steps
that must be taken to eliminate them. A
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significant component in this process is the
understanding of Overall Equipment Efficiency
(OEE). Ultimately, OEE is a tool that teaches us
about the “hidden capacity” of an organization
just waiting to be explored.
Six major losses indicated by OEE
Equipment failure causes production downtime.
Equipment failure requires maintenance
assistance and can be prevented with the use of
appropriate preventive maintenance actions,
developed and applied operating procedures, and
design changes. Most importantly, equipment
failure requires an improvement effort that
should be the result of a successful partnership
between production and maintenance. Predictive
maintenance techniques such as vibration, oil,
and thermo graphic analysis can be used to
anticipate equipment failure. If the failure
occurs, it is important to use root cause failure
analysis (RCFA) techniques to identify the root
cause of the problem and effective and
applicable solutions that will eliminate or
mitigate the failure occurrence and impact.
Setup and adjustments: this refers to loss of
productive time between product types, and
includes the warm-up after the actual
changeover. Changeover time should be
included in this loss opportunity and it should
not be part of the planned downtime.
Small stops are typically less than 5-10 minutes
and they are typically minor adjustments or
simple tasks such as cleaning. They should not
be caused by logistics.
Speed losses are caused when the equipment
runs slower than its optimal or designed
maximum speed. Examples include machine
wear,
substandard
materials,
operator
inefficiency, equipment design not appropriate
to the application, etc.
Losses during production include all losses
caused by less-than-acceptable quality after the
warm-up period.
Losses during warm-up include all losses caused
by less-than-acceptable quality during the warmup period. The three major categories of OEE
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The first category is availability. Availability
can be expressed with these formulas:
Availability = (Planned production time –
unscheduleddowntime)
Planned production time
Production time = Planned production time –
Downtime
Gross available hours for production include 365
days per year, 24 hours per day, 7 days per
week. Planned downtime includes vacation,
holidays, and not enough loads. From a pure
economic perspective, all available hours are
used for a true measure of OEE; however, from
a business and management view, equipment
may not be used at all times. This usually
happens due to market conditions or issues
associated with allocation of operating units in a
multi-site corporation with multiple operations
capable of producing the same products. Net
production time is the time during which the
products are actually produced. Speed losses,
small stops, idling, and empty positions in the
line indicate that the line is running, but it is not
providing the quantity it should. The third OEE
category is quality. Quality losses refer to the
situation when the line is producing, but there
are quality losses due to in-progress production
and warm up rejects. We can express a formula
for quality like this:
Quality (Yield) = (Number of products
processed – Number of products rejected)
(Number of products processed)
OEE tells how efficiently the equipment
produces during the time of its planned use. The
challenge of using OEE as a tool remains the
proper design of OEE to the specific plant,
production unit, and critical equipment level,
and the quantification and prioritization of these
losses that will ultimately become major
opportunities for the entire organization.
OEE FOR SADDLE AND LATHE BED
The equipment efficiency of Vertical Milling
Machine for this two components Saddle and
Lathe Bed were analyzed. Based on time
consumption and process the OEE is increased
after implementing the suggestions.
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Fault:
Chamfer is not done in the curved area of slot.
The program was not set to do chamfering.
Solution:
The operator was asked to program for
Chamfering in the curved area of the slot.
Benefits:
 The finishing operation was improved
and manual filing avoided.
 Improved quality
TIME STUDY REPORT
PERIOD
DURATION
PROCESS
(in min’s)
9.50-10.05
15
Machine idle
10.06-10.26
10.26-10.40
10.40-10.52
10.53-11.42
11.43-11.54
11.55-11.57
11.57-11.58
11.58-11.59
12.00-12.03
12.03-12.05
20
14
12
49
10
2
1
1
3
2
Face milling
Shoulder milling
Dovetail milling
End mill
Oil groove
Spot drill
14 drill
14.5 drill
22 counter bore
11 drill
12.05-12.07
12.07-12.09
12.09-12.10
2
2
1
18 counter bore
9 drill
15 counter bore
12.10-12.11
1
6.8 drill
12.11-12.12
1
5.5 drill
Quality (Yield) = (Number of products
processed – Number of products rejected)
(Number of products processed)
Number of products processed = 5
Number of products rejected = 1 (Defective
products are because of casting defect)
Quality (Yield) = [(5-1)/5]*100
Quality (Yield) = 80 %
Performance (Speed) = (Cycle time x Number of
products
processed)
IDLE REASON
Machine cleaning, job setting checking its
dimensions
12.12-12.14
2
3.8 drill
12.14-12.15
1
45 degree chamfer
12.15-12.19
3
90 degree chamfer
12.19-12.20
1
M8 taper
12.20-12.25
5
Machine idle
Removing the job cleaning.
12.25-12.30
5
Machine idle
MANUAL FILING
REMARKS: Chamfer is not done in the curved area of slot.
TOTAL MACHINING TIME
128 minutes
TOTAL IDLE TIME
25 minutes
Production time
 Consumption of time(4.5 minutes per
Performance = [(128*5)/ (153*5)]*100
job)
Performance = 83.66%
Availability = (Planned production time –
OEE
(OVERALL
EQUIPMENT
unscheduled
downtime)
EFFICIENCY) CALCULATION BEFORE
Planned production
MODIFICATION:
Availability = (153-0)/153 = 100%
OEE = 0.8*0.8366*1 = 0.66928 = 66.928%
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OEE
(OVERALL
EQUIPMENT
EFFICIENCY) CALCULATION AFTER
MODIFICATION:
Quality (Yield) = (Number of products
processed – Number of products rejected)
(Number
of
products processed)
Number of products processed = 5
Number of products rejected = 1(Defective
products are because of casting defect)
Quality (Yield) = [(5-1)/5]*100
Quality (Yield) = 80 %
Performance (Speed) = (Cycle time x Number of
products
processed)
Production
time
Performance = [(128.5*5)/ (148.5*5)]*100
Performance = 86.53%
Availability = (Planned production time –
unscheduleddowntime
Planned production time
Availability = (153-0)/153 = 100%
OEE = 0.8*0.8653*1 = 0.6922 = 69.22%
FIXTURE MODIFICATION FOR SADDLE
The component Saddle undergoes the operation
Angle Milling 90°, Dovetail 150°, drilling and
32 mm slot. All these operations are carried out
in HMCBut VMC can be used for dovetail 150°,
drilling, 32 mm slot operations.But due to a
problem in Fixture Plate it was not carried out in
VMC and all the operations were carried out in
HMCThe problem is that there is a 15mm
thickness rib. So while the operation is carried
out 15 mm key has to be placed.When there is a
Vibration the job may move & fall downThis
results in waste of time resetting the job, taper
was formed in the job, and finishing operation is
poor.
MODIFICATION
In the fixture plate (Preparatory plate) Profile is
taken in tightening block and butting block.The
job was clamped in this plate & the above
operations were carried out in VMC itself.
BENEFITS
Speed of VMC (7000rpm) is higher than HMC
(6000rpm).
Consumption of time.
Increased accuracy.
Benefits in usage of tools.
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OEE
(OVERALL
EQUIPMENT
EFFICIENCY) CALCULATION BEFORE
MODIFICATION:
Quality (Yield) = (Number of products
processed – Number of products rejected)
Number of products processed = 5
Number of products rejected = 1
Quality (Yield) = [(5-1)/5]*100
Quality (Yield) = 80 %
Performance (Speed) = (Cycle time x Number of
products
processed)
Production time
Performance = [(280*5)/ (415*5)]*100
Performance = 67.46%
Availability = (Planned production time –
unscheduled
downtime)
Planned production
Availability = (153-0)/153 = 100%
OEE = 0.8*0.6746*1 = 0.53968 = 53.96%
OEE
(OVERALL
EQUIPMENT
EFFICIENCY) CALCULATION AFTER
MODIFICATION:
Quality (Yield) = (Number of products
processed – Number of products rejected)
(Number of products processed)
Number of products processed = 5
Number of products rejected = 1
Quality (Yield) = [(5-1)/5]*100
Quality (Yield) = 80 %
Performance (Speed) = (Cycle time x Number of
productsprocessed)
Production time
Performance = [(255*5)/ (345*5)]*100
Performance = 73.19%
Availability = (Planned production time –
unscheduleddowntime)
Planned production time
Availability = (153-0)/153 = 100%
OEE = 0.8*0.7391*1 = 0.59128 = 59.12%
COMPONENT
2
:
LATHE
BED
SUGGESTED CHANGES
Utilizing KTM Vertical milling machine:
PROBLEM
The drilling and slotting operation carried out in
HMC takes 390 minutes and 60 minutes for
setting. Also 30 minutes for removal and
cleaning. So 480 minutes consumed to do this
operation per job. KTM Vertical milling
machine is in breakdown condition.
SOLUTION
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If this operation is done in KTM Vertical milling
machine HMC can be Utilized to perform other
operations
(OVERALL EQUIPMENT EFFICIENCY)
CALCULATION
BEFORE
MODIFICATION:
Quality (Yield) = (Number of products
processed – Number of products rejected)
(Number of products
processed)
Number of products processed =14
Number of products rejected =2
Quality (Yield) = [(14-2)/14]*100
Quality (Yield) = 85.71 %
Performance (Speed) = (Cycle time x Number of
products
processed)
Production time
Performance = [(70*14)/ (87*14)]*100
Performance = 80.45%
Availability = (Planned production time –
unscheduled
downtime)
Planned production
Availability = (153-0)/153 = 100%
OEE = 0.8571*0.8045*1 = 0.6895 = 68.95%
OEE
(OVERALL
EQUIPMENT
EFFICIENCY) CALCULATION AFTER
MODIFICATION:
Quality (Yield) = (Number of products
processed – Number of products rejected)
(Number
of
products processed)
Number of products processed =14
Number of products rejected =2
Quality (Yield) = [(14-2)/14]*100
Quality (Yield) = 85.71 %
Performance (Speed) = (Cycle time x Number of
products
processed)
Production
time
Performance = [(60*14)/ (73.5*14)]*100
Performance = 81.63%
Availability = (Planned production time –
unscheduled
downtime)
Planned
production time
Availability = (153-0)/153 = 100%
OEE = 0.8571*0.8163*1 = 0.6996 = 69.96%
Using two Cutters
PROBLEM
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Since only one side cutter is used for width
correction operation it takes double the time to
correct the width
SOLUTION
Another cutter can be used on the other side of
the machine.
BENEFIT
If another cutter is used time taken for removal
and setting-(30 minutes) and milling the other
side-(40 minutes) per job can be utilized for
other operations.
OEE
(OVERALL
EQUIPMENT
EFFICIENCY) CALCULATION BEFORE
MODIFICATION:
Quality (Yield) = (Number of products
processed – Number of productsrejected)
(Number of products processed)
Number of products processed =14
Number of products rejected =2
Quality (Yield) = [(14-2)/14]*100
Quality (Yield) = 85.71 %
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