Implementation of Six Sigma to Service Quality Management in Auto After-sale
Xiang-ping Bo1, Yi-yi Wang2, Jun-fang Zou3
1
School of Business Administration, Hunan University, Chang Sha, China
School of Business Administration, Hunan University, Chang Sha, China
3
School of Business Administration, Hunan University, Chang Sha, China
(1boxiangping@yahoo.com.cn, 2wangyiyi_2008@yahoo.cn)
2
Abstract - Based on the characteristics of service
industry, this paper constructs an implementation model for
automobile service quality management and achieves
excellent results in the service quality improvement project
in after-sale maintenance center. It proves that Six Sigma
can be applied in automobile service industry, and some
suggestions for Six Sigma implementation in service
industry are proposed : firstly, making some necessary
adjustments according to the specified situation in the
enterprises; secondly, gaining support from the executives;
lastly, paying close attention to the customer demands and
making decisions on the basis of data and facts.
Keywords - Six Sigma, auto after-sale service, service
quality management, process improvement
I.
INTRODUCTION
With the speedy improvement of domestic auto
manufacturing technology and the maturity of the
consumption concept of customers, auto brand
competition has transferred from internal factors such as
product technology and price to after-sale services. So far,
auto after-sale service quality has remained to be
improved, scientific management and analysis methods are
desperately needed for management guidance.
Six Sigma is a good management method to improve
quality management in processes intensively and
effectively. Since Six Sigma lays much on processes,
people think that it is not suitable for service enterprises
because its processes and products are intangible, mutable
and perishable. But this research has shown that Six Sigma
is suitable to the auto after-sale service processes. It has
proved that Six Sigma is effective for the service industry
and can be taken as a reference for other service sectors.
II. LITERATURE REVIEW
A.
Six Sigma
Many researchers have studied Six Sigma programs
and identified many critical decisions of these programs.
Six Sigma is a management system for achieving and
maintaining success by concerning customers, process
improvement as well as effective using data and facts [1].
The key idea in Six Sigma is through the process
improvement to improve customer satisfaction and
increases the firms profits[2],with main features including
the real focusing on customers, the management and
improvement based on facts and data driven, active
management and no boundary cooperation.
B.
Implementation Model
As discussed before, a model for effectively guiding
the implementation of Six Sigma is not available. Lee
Mortimer(2006) considered the DMAIC methodology to
be essential to six sigma programs and appropriate for
delivering business improvements[3]. Bis(2007) considered
DMAIC as the scientific method in Six Sigma programs.
According to Franza (2009), DMADV was central to a
product development experience. But there are great
improvement demands and opportunities in service areas.
So four steps model of Six Sigma and five steps model are
put forward and they have played an effective role beside
the factory scope in nonwoven field[1].
C.
Critical Success Factors of Six Sigma
Snee and Hoerl (2007) think that the success factors
of Six Sigma are leadership support and participation,
outstanding talents, and basic support systems three
elements[12]. Through the questionnaire surveys, Ho and
Chuang (2008) have found out that the senior managers
participation and support, the Six Sigma team, education
and training and considering customers as the center etc.
are the key factors to successfully implement Six
Sigma[13]. Schroeder et al. (2010) conclude five important
factors, namely, senior managers support and
participation, experts of Six Sigma, a Six Sigma team,
according to the DMAIC system in Six Sigma
implementation[14]. The other scholars argue that
understanding Six Sigma and incentives, project choosing
and management experience, concentrating and
communicating with customers, outstanding talents,
connecting with strategic and suppliers, clear standards of
performance will also have the effect on the
implementation of Six Sigma [4-8] .
D.
Suggestions to the Implementation of Six Sigma
Scholars have put forward many suggestions to the
implementation of Six Sigma. Kwak and Anbari (2008)
view that when the enterprises implement Six Sigma, they
must regard customers as the center[9]. Satya (2009)
points out that enterprises should pay more attention to
the training and education of the workers to make the
employees understand the Six Sigma, change the
enterprise culture, and establish an effective incentive
mechanism[10]. But Hua Zhao(2004) emphasizes that
implementing Six Sigma in China, the companies must
pay attention to the Chinese cultural characteristics, and
can not copy the foreign methods mechanically[11]. Pande
(2011) argues that carrying out Six Sigma in the service
industry should note the following four points: starting
from the beginning, regulating the process carefully,
using the facts and data well, not over-emphasizing
statistical analysis[1].
III. SIX SIGMA IMPLEMENTATION MODEL
IN SERVICE QUALITY MANAGEMENT
The implementation of Six Sigma in the service quality
management can not follow the Six Sigma system in
manufacturing quality management because of the service
characteristics. In this paper, the implementation model is
based on Pande's five steps model by adjusting the model
combined with the service process characteristics (Fig.1).
continuous improvement
Expand and integrate the
System Of six sigma
Develop and implement solutions
Analyze service process
Organization
support
Measure performance
Education
and training
Define customers’critical needs
Six sigma
team
Identify core service processes
Senior
leaders’
support and
attendance
Six sigma implementation paths
Link to
customer
Focus on
data and
facts
Analyse
process
processes, especially the poor performance processes, and
the possible causes by drawing detailed service flow chart.
5. Putting forward the Solutions. Put forward several
improvement solutions to the main problems firstly and
then adjust the process or design a new process based on
the most feasible solutions. A continuous assessment on
the improvement effect to the implementation of the new
solutions should be operated and the implementation of
the new solutions should be controlled.
6. Expanding and Integrating the System of Six Sigma.
Expand the range of the improved processes to push over
the improvement efforts continually and implement the
closed loop management.
7. Organization Support. The implementation of Six
Sigma must gain the support and attendance from the
senior leaders. It also depends on an effective organization
team to promote the continuous improvement. The
education and training of the employees are necessary to
improve service consciousness and quality improvement
skills and increase the possibility of success.
8. Concept Support. The implementation of Six Sigma
must concentrate on customer demands, communicate
with customers effectively and design products and
services based on customers' demands in order to improve
customer satisfaction. The decisions are made based on the
data and facts not on the feelings and experience. The Six
Sigma in service quality management must analyze the
service processes to find out the improvement chances and
improve service quality by improving the service process
ultimately.
Concept
support
IV.
IMPLEMENTATION CASE: SERVICE
QUALITY IMPROVEMENT PROJECT IN AUTO
AFTER-SALE
Figure 1 Six Sigma implementation model in service quality
management
As shown in Fig.1, the model includes Six Sigma
implementation paths and support systems. There are six
implementation paths, including identifying the core
service process, defining the customer critical needs,
measuring the performance, analyzing the service
processes, designing and implement solutions, expanding
and integrating the system of Six Sigma. The support
system includes organization support and concept support.
1. Identifying the Core Service Processes. The core
processes are the most important part of the link to
creating value and affecting customer satisfaction directly.
Since service process is intangible, drawing the diagram of
core processes can help the project members to understand
the whole process better.
2. Defining the Customer Critical Needs. Critical
needs are the needs that can not been fully satisfied but
important to customer satisfaction. They should be found
out and defined firstly in the project.
3.Measuring the Performance. Measuring performance
is to measure the quality characteristics of critical demands
to set up an improvement goal.
4. Analyzing the Service Processes. Analyzing the
service processes is to find out the problems in the
As the competition becomes intensively, TC Auto
Sales and Service Co. Ltd. decide to implement the Six
Sigma model in auto after-sale service center to improve
service quality and increase customer satisfaction.
A.
Preparatory of the Implementation
In order to promote the implementation smoothly, TC
has done lots of preparatory work:
1) Setting up a six sigma team
The general manager is the advocate who is
responsible for the overall project. The other members are
responsible for the cooperation and communication in
different departments.
2) Education and training
The training includes the service awareness training
and the training of quality improvement methods and
tools.
B.
1)
Implementation of the Model
Identifying the core processes
The core process of the auto after-sale is the
maintenance service, which includes reception, operation
and delivery processes (Shown in Fig.2).
Reception Operation
Reception
Fault Diagnosis
Car
Washing
Completion
Checking
Delivery
Testing and Settlement
Figure 2.
Valuation
Operation
Accessories
Receiving
Dispatching
Delivery the Vehicle
Core service process of after-sale service center
2)
Defining the critical needs of customers
The critical needs of customers are defined by the
investigation the service quality of the after-sale service
center which is the gap between the perceived quality and
expected quality and the importance of customer needs.
The quality questionnaire is adopted Likert 5 point scale
and divided into three parts of the importance of quality
factors, the expected quality and perceived quality. We
regained 131 valid questionnaires and established the
matrix of service quality-importance, the plot is divided
into four quadrants by the average of scores of service
quality and importance (Shown in Fig. 3).
Figure 3.
The matrix of service quality - importance
It can be seen that the critical needs are maintenance
cost and service time consuming in Fig.3 and these two
quality elements should be improved firstly. The
maintenance cost is uniform priced by the manufacturer.
So shortening service time-consuming is the preferred
improvement project.
3) Measuring performance
According to the core process in after-sale service, the
time spending in the center includes the reception,
operation and delivery time. The dispatching time is listed
separately because of its long time. The vehicle arrival
time (t0), billing time (t1), dispatching time (t2), completion
time (t3) and delivery time (t4) are taken as the measure
nodes. The reception time(T1), dispatching time(T2),
operating time(T3) and settlement time(T4) according to
Tn=tn-tn-1(n=1, 2, 3, 4) and the total time(T) can be
calculated (Shown in Fig.4).
Arrival
time（t0）
Billing
time（t1）
Reception
time（T1）
Dispatching
time（t2）
Dispatching
time（T2）
Completion
time（t3）
Operation
time （T3）
TABLE I . TIME -CONSUMING STATISTICAL ANALYSIS TABLE
Before Improvement
After Improvement
Mean (m)
Percent
Mean (m)
Percent
Reception Time
6.26
4.47%
11.05
10.14%
Dispatching
19.95
14.58%
12.33
11.31%
Time
Operating Time
83.68
61.11%
69.73
63.96%
Settlement Time
27.01
19.74%
15.91
14.59%
Total Time
136.90
100%
109.02
100%
According to Table I, the operating time is about 84
minutes, more than 60% of the total time. Therefore, it is
the key to shortening customers' waiting time to improve
the operational efficiency and eliminate unnecessary
operation process. The sum of dispatching and settlement
time is more than 47 minutes and accounts for 35% of the
total time which is very short. It shows that the problem is
very prominent and the processes need to be improved
urgently.
4) Analyzing the service process
The detailed service flow chart is drawn out based on
the actual situation in the after-sale service centers. The
problems are found out by identifying the coherent
processes, bottlenecks, redundancy, rework links etc. They
are the fault diagnosis, valuation, dispatching, parts
supply, operation, settlement etc.. The fault diagnosis,
careless checking may cause incomplete fault diagnosis.
And some new faults in the operation process may be
found by the maintenance technicians. All these would
waste lot of maintenance time and lengthen the operation
time.
5) Putting forward the solutions
The improvement solutions are put forward
according to the problems which are found out by
process diagnosis individually. For example, the feasible
improvement solution for fault diagnosis process is to
divide the fault diagnosis process into reception station
diagnosis and diagnostic station diagnosis. The six
position checking is implemented strictly to confirm the
fault and the cause of the malfunction on the reception
diagnosis station. A further diagnosis is needed on the
diagnosis station for those can’t be determined the
malfunction cause on the first diagnosis station.
To verify the effectiveness of the process
improvement, 66 repaired vehicles for the service time
consumption are selected to do the independent samples T
test at significant level before and after the improvement.
The result is shown in Table I and Table II.
TABLE II.
Delivery
time（t4）
Settlement
time（T4）
Figure 4. The diagram of time measurement program
140 maintenance vehicles are selected to be recorded
for the service time-consumption and 131 effective
samples are collected finally. The results are shown in
Table I.
Equal variances
assumed
T
Equal variances
not assumed
INDEPENDENT SAMPLES TEST
Levene's Test
t-test for Equality of
for Equality of
Means
Variances
F
Sig.
t
df
Sig.
15.276
0.000
2.019
2.462
195
0.045
194.98
0.015
From the Table I and Table II, it is seen that the P
value is 0.015<0.05, which certifies that the total time
before and after the improvement are different
significantly and the vehicle maintenance total time
consumption is 109.09 minutes. It has been shortened
17.88 minutes. And the dispatching, operating and
settlement time are shortened 7.62, 11.1 and 13.95 minutes
separately. It shows that the process improvement makes
successful result in the after-sale service center .
6) Expanding and integrating the six sigma system
Expand the range of improved process to push over the
improvement efforts continually. Firstly, publicizing the
improvement achievement to the managers and employees
in order to reduce the resistance. Secondly, developing
solutions in advance to the potential problems. Thirdly,
assigning process manager and clarifying the
responsibility. Finally, implementing the closed-loop
management in the other field.
V. CONCLUSIONS
Considering the specific characteristics of service
industry, this paper constructs a Six Sigma implementation
model in service quality management and is applied in
service quality improvement project in an auto after-sale
service center. Conclusions and suggestions are as
follows:
1. Six Sigma can be applied to service industry. Six
Sigma is not only the methodology concentrated on
processes but also a strategic way of improvement to all
processes and products. Six Sigma management method is
also suitable for service enterprises because the service is
made up of processes. This article has shown the
successful result.
2. It needs necessary adjustment according to the
present situations of the enterprise before applying Six
Sigma to service industry. Service processes and products
are intangible and perishable, which are not easy to
measure. The priority of the implementation of Six
Sigma is how to visualize the service processes and
quantify the service products. Six Sigma model of service
industry must start with the service processes, analyze
processes and improve service processes.
3. The service enterprises should note in the
implementation of Six Sigma. Firstly, support and
participation from senior leaders can help remove
obstacles of implementing Six Sigma but also guarantee
the cooperation among different departments. Secondly,
pay more attention to customer demands. Thirdly, make
decisions on the basis of the data and facts instead of
feeling and experience.
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