DOI : 10.17577/IJERTV6IS090098
- Open Access
- Total Downloads : 146
- Authors : Sujith N S, Thimmaiah A G, Jnanesh M, Kaveriappa M B
- Paper ID : IJERTV6IS090098
- Volume & Issue : Volume 06, Issue 09 (September 2017)
- DOI : http://dx.doi.org/10.17577/IJERTV6IS090098
- Published (First Online): 16-09-2017
- ISSN (Online) : 2278-0181
- Publisher Name : IJERT
- License:
This work is licensed under a Creative Commons Attribution 4.0 International License
Study and Analysis of Equipment Availability Using TPM Tools in an Extrusion Plant
Sujith N S1, Thimmaiah A G2
Assistant Professors, Department of Mechanical Engineering,
Coorg Institute of Technology, Ponnampet, Kodagu, India
Jnanesh M3, Kaveriappa M B4
Assistant Professors, Department of Mechanical Engineering,
Coorg Institute of Technology, Ponnampet, Kodagu, India
AbstractExtrusion is a critical process which involves a number of steps like casting of logs, heating of logs and dies to the preset temperature. Maintaining extrusion pressure and temperature at the press plays a major role in extruding of profiles. Precautionary measures have to be taken for suitable alignment of container and setting of dummy block. Breakdowns occur due to the use of equipments like conventional container, die, dummy block which directly implies on less recovery. By upkeeping the equipments, plant performance will increase and higher productivity can be achieved. By adapting maintenance tools Total Productive Maintenance (TPM) tools we can improve the plant performance considerably. TPM tools such as Kaizen and Why-Why analysis are adopted here to improve the plant performance.
This work is envisaged to analyze the breakdowns, their causes and actions to be taken and thereby study their effect on equipment availability and to improve the plant performance.
Keywords Total Productive Maintenance, Root Cause Analysis, Kaizen, Why-Why Analysis, Extrusion
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INTRODUCTION
Extrusion is a process used to create objects of a fixed cross- sectional profile. Here material is pushed through a die of the desired cross-section. The advantages of this process over other manufacturing processes are its ability to create very complex cross-sections, and to work materials that are brittle, because the material encounters compressive and shear stresses.
It also forms parts with an excellent surface finish. It is a critical process which involves a number of steps like casting, heating of logs and dies to the preset temperature. in this process maintaining extrusion pressure and temperature at the press is very essential to achieve the desired shape and size. Suitable alignment of container and setting of dummy block plays a vital role in this process. Breakdowns occur due to the use of equipments like conventional container, die, dummy block which directly implies on less recovery, which leads to reduction in plant performance ease of use.
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OBJECTIVE
The objective of this work are to study breakdown data, analyze their causes and actions taken and its effect on equipment availability and to implement new ideas through TPM tools like Kaizen and Why-Why analysis.
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DATA COLLLECTION
The data pertaining to breakdowns in extrusion process like downtime were collected and shown in table 1 and table 2. The term downtime is used to refer a period when a system is unavailable. Data pertaining to both mechanical and electrical failure were collected separately for a period of six months. These data were used to determine equipment availability Performance rating were also determined.
Table 1: Total downtime in hours
Equipment
Month 1
Month 2
Month 3
Month 4
Month 5
Month 6
Tank 1
12
2.58
2.17
8.58
1
3.83
Tank 2
24.5
0.75
3.33
0.5
10.25
3.25
Tank 3
0
14
0
0
4.5
0
Coloring Tank
0.5
70.58
0
0
5
0.5
Crane 1
1.5
1
0
0
0
10.84
Crane 2
19.5
1.75
0
0.25
0
0.17
Crane 3
8.65
2
0
3.5
0
0
Chiller 1
2.5
1
0
0
0
3
Chiller 2
4
2.25
0
0
0
0.17
Chiller 3
0
1
0
0
0
0
Chiller 4
0
0
0
0
0
0
Thermo Pac
0
0
0.33
0
0.83
0
Total
77.17
96.9
45.83
60.83
66.58
40.76
Table 2: Overall frequency of downtime
Equipment
Month 1
Month 2
Month 3
Month 4
Month 5
Month 6
Tank 1
5
2
2
2
4
2
Tank 2
8
1
3
2
4
1
Tank 3
0
4
2
5
3
0
Coloring Tank
1
6
2
0
2
1
Crane 1
1
1
0
1
2
3
Crane 2
5
2
0
1
0
1
Crane 3
3
1
3
0
0
0
Chiller 1
2
1
0
0
2
2
Chiller 2
2
1
0
0
0
1
Chiller 3
0
2
0
2
0
3
Chiller 4
1
0
2
0
4
0
Thermo Pac
2
0
3
0
0
4
Total
32
21
17
13
21
18
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DETERMINATION OF EQUIPMENT AVAILABILITY AND PERFORMANCE RATING
Equipment Availability:
The simplest representation for availability is a ratio of the expected value of the uptime of a system to the aggregate of the expected values of uptime and downtime
Performance Rating:
A procedure for determining the value for a factor which will adjust the measured time for an observed task performance to task time that one would expect of a trained operator performing the task, utilizing the approved method and standard working conditions.
Calculation of Equipment Availability and Performance Rating is shown in table 3
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ROOT CAUSE ANALYSIS
Root cause analysis (RCA) is method used to identify the root cause of the problems or events. By directing corrective measures at root causes, it is more probable that problem reoccurrence will be prevented. However complete prevention of re occurrence is not always possible. RCA is often considered to be an iterative process and is frequently viewed as tool of continuous improvement.
This analysis is performed by
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Cause and effect diagram
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Why-Why Analysis
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Kaizen
-
-
Cause and Effect Diagram
It is used to determine the primary and secondary causes for the breakdown of various equipments. In this analysis the causes of breakdown are classified into major categories like machine, materials, people, methods, policies etc. Identify all possible causes and label each causes under appropriate category. Analyze the causes and rank the most likely ones for further consideration and study.
The cause and effect diagram for the breakdown of anodizing tank, crane, motor, pump, chiller and rectifier was prepared and the primary and secondary causes for the breakdown of the above equipments were identified.
-
Why-Why Analysis
It is conducted to identify solutions to a problem that addresses its root causes. Rather than taking action that are merely band aids, a why-why helps you to identify how to really prevent the issue from happening again.
To solve a problem using why-why analysis, initially identify the problem and then ask Why is the problem taking place. This will end up with number of answers. Repeat this process at least five times for each of the answers, so that the root causes are identified.
The Why-why analysis for anodizing tank, crane, motor, pump, chiller and rectifier was prepared and the root causes for the breakdown of the above equipments were identified.
-
Kaizen
Kai means change, Zen means good, Basically Kaizen is for small improvements, but carried out on a continual basis and involve everyone in the organization. It requires no or very little investment. The principle behind this is A very large number of small improvements are more effective in an organizational environment than a few improvements of large value
Table 3: Calculation of Equipment Availability and Performance Rating
Months
Planned Availability
Actual Production
Total Downtime
Total Available Time
Total Operating Time
Equipment Availability
Performance Rating
Month 1
95
164
109.15
720
614.85
84.924
88.821
Month 2
95
152
128.9
744
615.09
82.674
82.29
Month 3
95
164
85.83
720
630.17
88.012
86.662
Month 4
95
157
92.83
744
651.17
87.522
80.287
Month 5
95
160
98.58
744
645.42
86.75
82.55
Month 6
95
162
80.76
720
638.24
88.76
84.523
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RESULTS
After performing root cause analysis data collected are shown in table 4 and table 5. Equipment Availability and Performance rating are determined as shown in table 6.
Table 4: Total downtime in hours
Equipment
Month 1
Month 2
Month 3
Month 4
Month 5
Month 6
Tank 1
8.36
13.38
2.77
1.51
2.87
1.47
Tank 2
0.85
1.6
11.6
0.78
0
6.39
Tank 3
0
1.19
0.11
9.49
0
5.75
Coloring Tank
0
6.97
1.99
0
3.77
0
Crane 1
2.16
1.33
0
1.63
0
12.66
Crane 2
1.3
0
0
0.23
1.69
1.98
Crane 3
0
0
4.37
0
0
0
Chiller 1
0
0
0.26
0
0
0
Chiller 2
0
0.78
0
0
0
0
Chiller 3
0
0
1.11
0
0
0
Chiller 4
0
0
0
0
0.31
0
Thermo Pac
1.38
0
2.28
0
0
0
Total
14.5
25.25
24.5
13.64
8.64
28.25
Table 5: Overall frequency of downtime
Equipment
Month 1
Month 2
Month 3
Month 4
Month 5
Month 6
Tank 1
4
6
1
2
2
1
Tank 2
2
1
1
1
0
4
Tank 3
0
2
1
2
0
2
Coloring Tank
0
3
2
0
3
0
Crane 1
2
1
0
1
0
2
Crane 2
2
0
0
1
1
1
Crane 3
1
0
3
0
0
0
Chiller 1
0
0
1
0
0
0
Chiller 2
0
2
0
0
0
0
Chiller 3
0
0
2
0
0
0
Chiller 4
0
1
0
0
1
0
Thermo Pac
3
0
2
0
0
0
Total
13
16
13
7
7
10
Table 6: Calculation of Availability and Performance Rating
Months
Planned Availability
Actual Production
Total Downtime
Total Available
Time
Total Operating
Time
Equipment Availability
Performance Rating
Month 7
95
200
46.05
744
697.95
93.810
95.42
Month 8
95
188
57.25
720
662.75
92.048
94.46
Month 9
95
197
64.5
744
679.5
91.330
96.54
Month 10
95
200
45.64
744
698.36
93.866
95.36
Month 11
95
201
40.64
574
533.36
92.920
94.21
Month 12
95
189
60.25
720
665.8
91.701
94.52
Comparison of Equipment Availability and Performance Rating before and after root cause analysis
Fig.1 Comparison of Availability before and after root cause analysis
Fig.2 Comparison of Performance Rating before and after root cause analysis
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CONCLUSION
-
After performing root cause analysis and implementing kaizen for certain machines/equipments it is observed that equipment availability and performance rating has increased. This is because of proper diagnosis of the problem through root cause analysis and by bringing some improvements to the existing system through kaizen implementation. Whenever a breakdown occurs the root causes for such breakdowns has to be identified and some improvements should be made to prevent the occurrence of similar breakdowns.
REFERENCE
[1]. Lindley R Higgins Maintenance Engineering Handbook, Mc Graw Hill Book Company, 1988. [2]. H P Garg Industrial Maintenance, Rajendra Printers Pvt. Ltd, New Delhi, 1972. [3]. Robert C Rosaler and James O Rice Industrial Maintenance Reference Guide, Mc Graw Hill Book Company, 1987. [4]. SeiiChi Nakajima TPM An Introduction to Total Productive Maintenance, Productivity Press (INDIA) Private Ltd, 1993. [5]. Charles E Ebeling Reliability and Maintenance Engineering, 5/E Tata Mc Graw Hill Book Company, 2005. [6]. R P Mohanthy and R R Lakhe TQM in Service Sector, Jahico Publishing house, 2002