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International Journal of Mechanical Engineering and Technology (IJMET)
Volume 10, Issue 03, March 2019, pp.1025-1037. Article ID: IJMET_10_03_103
Available online at http://www.iaeme.com/ijmet/issues.asp?JType=IJMET&VType=10&IType=3
ISSN Print: 0976-6340 and ISSN Online: 0976-6359
© IAEME Publication Scopus Indexed
OPERATIONAL IMPROVEMENT BY LEAGILE
APPROACH
Krishnamoorthy S
Department of Mechanical Engineering, Sri Krishna College of Engineering and Technology
Coimbatore, Tamilnadu, India.
Ben Ruben R
Department of Mechanical Engineering, Sri Krishna College of Engineering and Technology
Coimbatore, Tamilnadu, India.
ABSTRACT
This research work is carried out in a air compressor manufacturing company
which produces different models of air compressors. The work aim was to improve the
productivity by reducing the total operating cycle time, unnecessary motions, material
handling, and to create a standardized working environment. Two stations namely drive
and lubrication assembly and testing were found out to be the bottleneck stations, and
efforts are taken to improve its productivity. Kaizen’s were planned for improvement
activities and were implemented subsequently. These improvement actions were based
on Lean production organizational model and application of Lean tools. The current
agility level of the firm was calculated and suggestions were given to improve the agility
level of the firm.
Keywords: Leagile, Testing, Kaizen, Agility Assessment, New Product Development.
Cite this Article: Krishnamoorthy S and Ben Ruben R, Operational Improvement by
Leagile Approach, International Journal of Mechanical Engineering and Technology,
10(3), 2019, pp. 1025-1037.
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1. INTRODUCTION
Lean manufacturing is focused on eliminating wastes in the entire manufacturing process. It
deals with minimizing work -in progress, eliminating processes that do not add value to the
product, making the process more flexible to make products of different design without
changing the value of the product. Many manufacturing companies, historically, have been able
to maintain bloated or inefficient methods because of a protected market, strong brand strength
or huge profit margins. The global competition is forcing these manufactures to quickly change
their methods to be less wasteful, and provide value to their customers through customization
and reduced cycle or delivery times. There are five-key principles that must be followed to
implement lean manufacturing successfully. They are,
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1. Specify value from the standpoint of the end customer by product family.
2. Identify all the steps in the value stream for each product family, eliminating whenever
possible those steps that do not create value.
3. Make the value-creating steps occur in tight sequence so the product will flow smoothly
toward the customer.
4. As flow is introduced, let customers pull value from the next upstream activity.
5. As value is specified, value streams are identified, wasted steps are removed, and flow
and pull are introduced, begin the process again and continue it until a state of perfection
is reached in which perfect value is created with no waste.
Agile manufacturing is a term applied to an organization that has created the processes,
tools, and training to enable it to respond quickly to customer needs and market changes while
still controlling costs and quality. The definition of leagility, a system in which the advantages
of combination of lean and agile principles are combined was originally developed to
manufacturing supply chain. The two paradigms lean thinking and agile manufacturing may be
distinctly different but they are combined for an effective successful mechanism which
eliminates the non-value adding activities and increases the flexibility of the system. Leanness
means developing a value stream to eliminate all wastes including time to ensure a leveled
schedule. Agile ensures that the system is completely flexible and responds to the
unpredictability. These two distinct features are combined o create a system which facilitates
flow and is flexible to the volatile market.
2. LITREATURE REVIEW
J. Womack et al [1] discussed briefly about the lean methodology and the various key principles
that must be adopted to establish a lean environment. Y. Monden et al, [2] discussed about the
Toyota production system and the various tools and techniques which they applied to their
organisation. M. Holweg[3] proposed a model that followed the one piece flow principle and
the changes that are to be adopted to achieve it. D. Jones et al, [4] proposed the concepts of lean
thinking and also they framed a model for achieving the lean production system. M. Imai[5]
discussed about the kaizen approaches that are adopted in the production line that aims for
continuous improvements in both the process and the system. It also empathised the formation
of a cross functional team in arriving better results This is the sequel to the author’s earlier
successful book, Kaizen. It also summarizes and extends much of the earlier work with
examples and case studies. “Gemba Kaizen” means continuous improvement in the workplace.
J. Liker[6] discussed about the 14 management principles which was followed by Toyota and
also explained about the need for practicing the mentioned principles. ] M. Rother[7] et al,
provided the usage of 5s and value stream mapping to identify the value adding and non value
adding activities and also about the ways prescribed to eliminate the typical wastes. The
Productivity Press Development Team [8] proposed a standard operating procedure that has to
be followed in the shop floor to eliminate the unnecessary motions and other waiting activities.
K. Suzaki [9] proposed a model which motivates the firm to achieve continuous improvements
by using the lean tools and also the importance of forming a cross functional team. M. L.
Spearman et al [10] proposed an integrated model to achieve pull system by consistent
elimination of wastes. Emiliani, B et al,[11] framed a model that suits the business environment
for practicing the lean principles and also provided a framework for business process
reengineering. Kobayashi, I et al,[12] highlights 20 different skills in a broad perspective that
can be used to make the lean manufacturing journey possible. It also contains an evaluation
system that helps pinpoint facets where improvements are needed. Aitken et al[13] gave the
definition of leagility, a system which in which the advantages of leanness and agility are
combined which was originally developed for supply chains.. Mason-Jones et al.[14] discuss
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that lead time reduction and enhancing the information flow across the supply chain will
increase the agility in the supply chain. Their benchmarking experiment between TCT,
traditional, material lead time reduction and information lead time reduction supply chain
approaches shows that TCT will aid in responding quickly to the volatile demands. They also
illustrate that the Total Cycle Time reduction utilizes the synergized benefits that are available
from the reduction of both material and information lead time C.G. Sreenivasa et.al.[15]
proposed a model to assess the agility level of a firm through 30 criteria’s to measure the current
agility level.
The literature provided wide information about the lean manufacturing principles and its
applications at various business enterprises. The information gathered from the papers was
very useful in analysing the current production system and also gave useful information about
the modifications that must be made to the processes to achieve flow by consistent elimination
of wastes.
3. CASE STUDY
The selected air compressor manufacturing company is the leading manufacturer of air
compressors in India and one of largest manufacturer of air compressors in Asia. It is an ISO
14001: 4000 certified company and also holds a BS OHSAS 18001:2007 certification. This
company manufactures around 40 different varieties of air compressors. The company produces
a wide range of compressors. They are classified as Piston Compressors, Electric-lubricated
screw air compressors, Electric oil free screw air compressors, Portable compressors and
Railway compressors.
3.1. Assembly Sequence of EN Series Air Compressors
The assembly sequence of EN Series Screw Air Compressors consists of six different assembly
stations.. The first station is the Canopy dis-assembly and labelling where the canopy is being
dis-assembled into two parts namely top part and the bottom part, and after this the labelling is
done using a label fixing tool. The next station is the cooler assembly where the cooler is being
attached with the bottom canopy. Next station is the Drive and Lubrication Assembly, where
the motor and the air-end is being fitted with the bottom canopy. The next station is the electrical
assembly where the wiring and other electrical accessories are being fit with the assembled
compressor. Once after electrical assembly is done the next station is the testing, where the
assembled compressor is being tested at different conditions. After testing Pre -despatch and
Inspection is done where the compressor is packed and pre despatch operations are performed.
3.2. Identification of Bottleneck Process
The S0 line which comes under the Electric-Lubricated Screw Air Compressor category
basically produces two different types of compressor models namely A12 and A14. The
operational assembly sequence is same for both the models. The work aim was to improve the
productivity by reducing the total operating cycle time by 20% by using lean tools and also to
improve the agility level of the firm by using leagile approach. The net available time per shift
is 510 minutes, and the total operating cycle time for A12 and A14 models are 201 minutes and
220 minutes respectively as shown in figure 1. Now after studying the entire line, various
studies and analysis were done to reduce the total operating cycle
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Figure 1 Identification of bottleneck stations
3.3. Methodology
The methodology as shown in figure 2 was formulated on the basis of understanding the
existing system thoroughly and also by discussing with the line managers. The initial task was
to observe and understand the process, which gives a clear vision of the process and all activities
involved in that process. The next step was to perform the video study. Video study maps the
current process as it is done and waste capturing is done by analysing the video. Once after the
video is taken next process is to classify the elemental activities based on the video, and then
the elemental activity is segregated into value added and non value added activity. After
segregating the activities, the next step is to classify the activities based on the category of the
wastes and proper lean tools are identified to eliminate the wastes. Once when the waste gets
eliminated a proper sequence is formed to perform the task. Finally the results are compared
with the old process and the improvements are validated. Further for measuring the current
agility level the structure of the company was studied initially. Later the current agility level
was found out .Based on the score obtained the weak areas were found out and effort
suggestions were given to improve the current agility level
Figure 2 Methodology to improve the agility level
4. STAGE-1 PROCESS IMPROVEMENT
4.1. Process description of Stage-1
Canopy disassembly labelling and cooler assembly is the first station of the B1 line which
produces the A12 and A14 model compressors. Canopy is the body of the air compressor which
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has two parts namely the top and the bottom part. Here initially the canopy is brought to the
station with the help of trolleys from the stores and being dismantled into top and bottom part.
Later labelling is done on the top part and the cooler is attached to the bottom part. Fastening
is done with the help of pneumatic ratchets .Attach the provided gland with the panel. Now the
bottom canopy is sent for drive and lubrication assembly.
After completion of labelling and cooler assembly the next process is the drive and
lubrication assembly .In this process the motor and air-end which are considered as the crucial
parts of the air-compressor are being assembled with the bottom canopy. Later the pulleys, belts
and air hoses are being assembled to complete the drive and lubrication assembly.
4.2. Performing the video study
Once after the process was observed and studied, video study was performed for waste
capturing. The study was performed for A14 model compressor. Initially video study was done
for the stage-1(Canopy disassembly, labelling, drive and lubrication assembly).Based on the
activity the wastes was classified and the captured wastes were categorized as per the lean
wastes. The time distribution is shown in Table 1.
Table 1 Time distribution for stage-1
Description
Time ( min)
Total time for Stage-1
99.45
Total value adding time
48.05
Total non value adding time
51.50
4.3. Planning the Kaizen activities
After the classifying of wastes for A14 model compressor the next step was to plan for the
Kaizen’s to reduce the time spent on non-value adding activities. Before planning the kaizen’s
for stage-1(Canopy disassembly, labelling, drive and lubrication assembly) some general
improvements were planned ,and based on these suggested improvements, the kaizen’s were
planned. They are,
1. Best Point location for storing tools and materials to be planned
2. Details of tools to be provided
3. Feasibility for a slim module trolley
4. Provision of overhead hanging tool
5. Redesigning the layout
6. Provision of an air gun
7. Laying vinyl sheet were canopy is to be stored
8. Erection of a jib arm crane
9. Provision of a low cost automated table for drive and lubrication assembly
4.4. Kaizen activities implementation
4.4.1. Provision of kit material feeding trolley
4.4.1.1. Existing problem
In the current situation the materials needed for assembly arrives in two different bins and it
becomes difficult for the operator to search for the materials