IMPACT OF SERVICE QUALITY ON CUSTOMER SATISFACTION OF AUTOMATED TELLER MACHINE SERVICE: CASE STUDY OF A PRIVATE COMMERCIAL JOINT STOCK BANK IN VIETNAM

. One of key challenge for Vietnamese commercial banks is how to compete in the market place with commonly undif­ ferentiated services. The aim of this study is to investigate the impact of service quality performance on customer satisfaction on ATM service in a commercial bank in Vietnam. This study applies SERVPERF framework to analyze the data collected from a ques­ tionnaire survey and found that ASSURANCE and TANGIBLES factors significantly impact on the customer satisfaction.

transfers on the market were primarily carried out by cash. But now, there is a significant change when Vietnamese have altered their habit from cash payment to using bank transfers and ATM services.
Therefore, developing ATM service is one of methods to increase the competitive position of a bank in the market today in Vietnam. Indeed, ATM service is becoming a mean of transaction which is essential for banks to increase their competitiveness in the market. Together with the race of providing diversified services of transaction, Vietnamese commercial banks also find out how to improve the quality of ATM service and satisfy customers. Thus, assessing the quality of ATM service and researching the relationship between service quality and customer satisfaction for ATM service are meaningful to improve the quality of ATM ser vices of banks in the future.

Introduction
The fact that Vietnam became an official member of WTO in 2007 has opened a new page for the Vietnamese banking sector. Vietnamese commercial banks now must impro ve their competitiveness and exploit opportunities which are brought back from the opened market. The biggest challenge is the increasingly competitive pressure on the domestic market when Vietnam becomes more integrated, and demands of customers are changeable. In that sense, one of the most essential things Vietnamese commercial banks have to do is to improve service quality and diver sify product line to meet various needs of customers and thus helping the banking sector become more and more integrated positively into the development of the banking sector in the region and in the world.
By applying modern banking technologies, Vietnamese commercial banks have launched a new product and service such as Automated Teller Machine (ATM). The appearance of ATM service has changed the basic transaction method in Vietnam's economy. Previously, almost all transactions and those in Vietnam, especially on ATM service of banks, are still rare. There are even fewer researches that have applied the SERVPERF model to measure service quality in the banking sector in Vietnam. Traditionally, SERVQUAL mo del is used to measure service quality, thus applying the SERVPERF model is quite new in service quality measure ment in Vietnam. The objective of this research is to provide more empirical evidence for academics and practitioners by investigating the impact of service quality on customer's satisfaction for ATM service in Vietnam's commercial joint stock banks through using SERVPERF model. This research focuses on analyzing a case study of a private commercial joint stock bank (the Bank), to suggest solutions for itself and thus may generalize new findings for other commercial banks in Vietnam. The research uses quantitative method through questionnaire survey. Data collected from this survey was analyzed by SPSS 16.0 in order to find out the impact of service quality on customer's satisfaction for ATM service in the Bank. This paper is divided into 7 main parts. Beside this in troduction part, Section 2 provides literature review for the study. Research methodology is given in Section 3. Section 4 and 5 present research analysis and discussion. Recommendations for practitionners are given in Section 6. Finally, the paper provides a conclusion in Section 7.

Service quality and customer satisfaction
There may be numerous definitions of service quality. Service quality is a customer's overall impression of the relative inferiority or superiority of the organization and its services (Bitner, Hubbert 1994). Edvardsson, Thomsson and Ovretveit (1994) suggested that service quality is a service that fulfills the expectations of customers and sa tisfies their needs. Parasuraman et al. (1985) defined ser vice quality as "the global evaluation or attitude of overall excellence of services". So, service quality is the difference between customers' expectation and perceptions of services delivered by service firms. Nitecki, Hernon (2000) defined service quality in terms of "meeting or exceeding custo mer expectations, or as the difference between customer perceptions and expectations of service". In addition, one of important definitions is that the quality of service as perceived by customer is the result of an evaluation process in which they compare their perspective of service outcome against what they expected (Gronroos 2007).
Automated Teller Machine (ATM) is one type of innova tion that can mechanically accept deposits, issue withdrawals, transfer funds between accounts, and collect bills. ATM ser vice quality is defined as the customer's overall evaluation of the excellence of the provision of services through electronic networks such as Automated Teller Machine (ATM).
Measuring quality in the service sector is more com prehensive than measuring quality of the manufacturing sector because quality evaluations are not made solely on the outcome of a service; they also involve evaluations of the process of service delivery. One of many service quality rese arch models often used in the world nowadays is SERVPERF proposed by Cronin and Taylor (1992). This scale was based on the SERVQUAL scale (Parasuraman et al. 1985(Parasuraman et al. , 1988 which assessed service quality through the gaps between customer "expectations" -(E) and "perceptions" -(P). However, SERVQUAL has been criticized on its confusion, and SERVPERF was proposed by Cronin and Taylor (1992) in which the "expectation" -(E) component of SERVQUAL was discarded and instead the "performance" -(P) compo nent alone was used. Cronin and Taylor provided empirical evidence across four industries namely banks, pest control, dry cleaning, and fast food to collaborate the superiority of their "performance -only" instrument (Sanjay, Garima 2004). The scale measure performance of five service quality components termed Tangible, Reliability, Responsiveness, Assurance, and Empathy (Parasuraman et al. 1988).
The definition of customer satisfaction has been widely debated as organizations increasingly attempt to measure it. Customer satisfaction can be experienced in a variety of situations and connected to both goods and services. It is a highly personal assessment that is greatly affected by customer expectations.
Kotler defined customer satisfaction as the extent to which a product's perceived performance matches a buy er's expectations. If the product performance falls short of expectations, the buyer is dissatisfied. If performance matches or exceeds expectations, the buyer is satisfied or delighted (Kotler et al. 2005). Customer satisfaction is an important theoretical as well as practical issue for marke ters and consumer researchers. Customer satisfaction can be considered as the essence of success in today's highly competitive world of business (Vanniarajan, Anbazhagan 2007). In this study, customer satisfaction is defined as the levels of service quality performances that meet customers' expectations.

Relationship between service quality and customer satisfaction
Parasuraman stated that there is a distinction between service quality and customer satisfaction: perceived ser vice quality is a global judgment or attitude relating to the superiority of the service, whereas customer satisfaction is related to a specific transaction (Parasuraman et al. 1988). However, many researchers have investigated the relations hip between service quality and customer satisfaction. Cronin, Taylor (1992) tested this relationship and con cludes that perceived service quality leads to customer satisfaction. The other studies also conclude that service quality is the antecedent of satisfaction (Spreng, Mackoy 1996;Brady, Robertson 2001) and is the main factor which affects satisfaction (Ruyter et al. 1997). Sureshchandar et al. (2002) used a factor specific appro ach to test the relationship between service quality and customer satisfaction of different banks in India. These critical factors used are (1) core service or service product, (2) human element of service delivery, (3) systematization of service delivery: nonhuman element; (4) tangibles of servi ce -servicescapes, (5) social responsibility. Questionnaires comprising 41 items in total were distributed to 452 custo mers from 51 different banks, and then 277 completed qu estionnaires from 43 banks were obtained. Analysis results revealed that correlation statistics between service quality and customer satisfaction are reasonably high which de monstrated high relationships between service quality and customer satisfaction. Anber et al. (2011) conducted a research about servi ce quality perspectives and customer satisfaction in com mercial banks working in Jordan. The research examined the level of service quality as perceived by 260 customers and its effect on customer satisfaction with the question naire survey including 20 items to measure 5 dimensions of service quality (Reliability, Responsiveness, Empathy, Assurance, and Tangibles) and 5 items to measure customer satisfaction. The results indicated that these 5 dimensions of service quality have significant influence on customer satisfaction when 26.1% of customer satisfaction can be explained by them. Jha et al. (2014) attempted to find out the satisfaction level of customers in ATM services in Bihar, India. For this purpose, primary data was collected from 100 respondents of different bank ATM users of Bihar. This paper suggested that banks should focus on important aspects of user frien dliness, ATM functionality and availability of transaction receipts, security, and privacy as well as frequent monito ring and maintenance of ATMs. Banks should also improve ATM features to suit customers and use this medium to build a strong and a sustainable relationship with customers. Mwatsika (2014) researched customer's satisfaction with ATM banking in Malawi. The results are from 353 ATM card users where over half are satisfied with ATM services from their respective banks. The results have found that all service quality dimensions significantly correlate with customer satisfaction with ATM services and that reliability is the most important dimension followed by responsive ness, empathy, assurance and tangibles.
From these researches, it can be concluded that service quality and customer satisfaction have a positive relations hip in which service quality is an antecedent as well as an important factor impacting on customer satisfaction.

SERVPERF model
SERVPERF is a popular model for measuring service quality in the world. It has been used in many researches (Zhou 2004;Hudson et al. 2004;Do Tien Hoa 2007;Pham, Nguyen 2007). In SERVPERF model, five dimensions include: -Tangible includes physical evidences of the service such as appearance of physical facilities, equipments, personnel, etc. -Reliability involves the ability of the organization to perform the promised service dependably and accu rately. -Responsiveness concerns the willingness or readiness of employees to help customers and provide services. -Assurance refers to knowledge and courtesy of em ployees and their ability to convey trust and confi dence. -Empathy is individualized care and attention that the firm provides to its customers. In short, this study will apply the SERVPERF model to measure service quality of ATM in a private commercial Joint Stock Bank in Vietnam as well as its customer satis faction. Moreover, few researches have applied SERVPERF model to measure service quality in banking sector in Vietnam. Traditionally, SERVQUAL model is used to mea sure service quality, therefore applying SERVPERF model is quite new in service quality measurement in Vietnam. This study will contribute to the advancement of service quality measurement and it will become a reference or sample for other researches in the future.
To find out the relationship between customer satis faction and service quality, it is necessary to hypothesize the relationship among service quality dimensions, perceptions of customer and their satisfaction (Fig. 1.).

Designing questionnaire
The questionnaire survey includes mainly 24 observed items under SERVPERF model, in which 22 items are divided into 5 components of service quality: Tangible, Reliability, Responsiveness, Assurance, and Empathy; the 2 remaining variables are used to measure customer satisfaction. This measurement bases on a 5point rating scale which corresponds to 1 = strongly disagree, 2 = somewhat disagree, 3 = neither agree nor disagree, 4 = somewhat agree, 5 = strongly agree. Specifically, these variables can be described and encoded as follows (Table 1): -Reliability Component: representing the reliability and confidence of customers to the bank services, including 5 observed variables (From R1 -R5); -Responsiveness Component: representing the ability to quickly resolve customers' requirements, concerns or inquiries which are related to ATM Card, inclu ding 5 observed variables (From S1 -S); -Assurance Component: representing the qualification as well as polite and courteous attitude of ATM Card Issuing officers to customers, including 5 observed variables (From A1 -A5); -Empathy Component: representing the empathy and considerate caring to customers and provide custo mers with the best possible service, including 4 ob served variables (From E1 -E4); -Tangibles Component: is evaluated through the ap pearance outsides the ATM service facilities such as: Appearance and uniforms of the staff, including 3 observed variables (From T1 -T3).

Data sample
Information was collected from the surveys of customers coming to the Bank branches or transaction offices within Hanoi from February 17 to May 5, 2013. Direct interview accompanied with surveys are used to collect the infor mation. Samples were chosen in a random and convenient man ner, including all customers who are using the Bank ATM service, regardless of gender, age and financial capabilities. Analysis methods that are mainly used in this research are Explanatory Factor Analysis EFA and Multiple Regression Analysis. According to Hair et al. (1998), it is necessary to collect a data containing at least 5 samples in each observed variables in order to obtain Explanatory Factor Analysis.
This research model has 24 observed variables. According to the criteria -5 samples for an observed va riables the needed size of sample will be n = 120 (24 × 5).
To obtain the required sample size, 250 questionnaires were sent to interview. After two weeks, authors collected 200 questionnaires back including 14 invalid ones, which

A2
ATM card Issuing staff has a clear and understandable explanation to customers.

A3
Customers feel safety when make any transaction at ATM 14 A4 Bank staff is always gentle and polite.

A5
Customers put more and more trust and confidence in ATM staff after each transaction. E Empathy Component

E1
Whenever going for a transaction at bank, cus to mers are always warmly welcomed by receptionist.

E2
Whenever going for a transaction at bank, custo mers are always guided to the right parking area by safe guard.

E3
Bank staff always spends a lot of time to understand the concerns of customers.

E4
Bank staff always takes care for each and every individual customer. T Tangibles Component 20 T1 ATM Card has good appearance and suitable size 21 T2 The screen of ATM always displays clearly

T3
There is always instruction signboards put at the place ATMs installed which is easy for customers to identify. Customer Satisfaction

CR
Customers are totally satisfied with quality of the ATM Service 24 CS Customers will introduce the ATM Service to other people contained many blank answers. Therefore, after removing 14 invalid questionnaires, 186 remained questionnaires met the requirement on size of samples. With sample size is 186, the author will use SPSS 16.0 software to clean and process data.

Analysis methodology
The data collected will be refined and processed by SPSS 16.0 software. Several following analysis methods are used in this research to find out and test impact of the factors on the quality of ATM service.

Reliability analysis
This method assists analysts in removing irrelevant varia bles. It also helps evaluating the reliability of the measu rement by Cronbach Alpha coefficient. Variables which have itemtotal correlation less than 0.3 will be removed.
Measurements with Cronbach Alpha being greater than or equal to 0.6 can be deployed (Nunnally 1978;Peterson 1994;Slater 1995). Normally, measurements with Cronbach alpha from 0.7 to 0.8 will be used. Many researchers assume that those which have the reliability from 0.8 to nearly 1.0 are acceptable measurements.

Exploratory factor analysis
After assessing the reliability of measurements by Cronbach Alpha coefficient and removing unreliable variables, explo ratory factor analysis will be used to reduce and summarize the data. This method is very useful in determining the variable set necessary for the research as well as in finding the relationship between variables.
In exploratory factor analysis, the KMO index (Kaiser -Meyer -Olkin) is deployed to indicate the suitability of factor analysis. If the KMO index lies between 0.5 and 1, the analysis is suitable. .685 In addition, factor analysis depends on Eigenvalue in determining the number of factors. Only factors with Eigenvalue greater than 1 are kept in the model. Eigenvalue represents the varying element explained by factors.
One significant part of the factor analysis result table is the component matrix or rotated component matrix. This component matrix contains coefficients representing standardized variables by factors (each variable is a poly nomial of factors). Factor loading coefficients show the link between variables and factors. Those coefficients reveal how close the relationship between variables and factors is. As the research uses factor extraction -principal component method, factor loading coefficients must have weights gre ater than 0.5.

Regression analysis
After extracting factors from exploratory factor analysis EFA, we search the necessary assumption violations in the multiple linear regression model such as testing standar dized residual, testing Variance inflation factor VIF. If its assumptions are not violated, the multiple linear regression model will be used. And the adjusted R 2 depict how well the model has been built.

Reliability test
After making reliability test, all those 22 variables have the correlation greater than 0.3, so they are all accepted (Table 2). Moreover, as the Cronbach Alpha coefficient is more than 0.6, the reliability component measurement is qualified. Those variables will be included in the next factor analysis.

Exploratory factor analysis (EFA)
ATM service quality measurement of the Bank is in accor dance with SERVPERF model, comprising 5 main com ponents with 22 observed variables. All 22 variables have passed the reliability test by Cronbach alpha coefficient. Exploratory factor analysis EFA is utilized to reassess the convergence of observed variables around the main com ponents (Table 3).
KMO and Barlett's test in factor analysis show that KMO index is high at 0.904 (greater than 0.5) with the significan ce equal to 0 (sig = 0.000). It can be concluded that EFA is suitable for the analysis.
Applying the extraction method: principal compo nents analysis and varimax rotation method at every level of Eigenvalues greater than 1 and, analyzing variables which has been extracted 5 from 22 observed variables and with cumulative variance is 60.427% (greater than 50%) satisfied.
Based on the analysis of the Rotated Component Matrix table, there are 5 Reliability components, including: R1;

Customer satisfaction scale analysis
The analysis of KMO and Bartlett's test of sphericity shows that the analysis of EFA is rather suitable, with KMO coef ficient = 0.500 and Sig value = 0.000.
Customer satisfaction scale has been extracted into one component that is greater than Eigenvalue 1 (Table 4). Furthermore, the two customer satisfaction loading co efficients are all greater than 0.4. According to that, after applying EFA for customer satisfaction, the two remaining variables were extracted into 1 component: Customer Satisfaction (CS).

Regression analysis
In multiple regression analysis, dependent variable is Customer Satisfaction (CS) and independent variables are Reliability component ( Tangibles component (T). The mean value of independent and dependent variables was calculated before conducting multiple regression analysis. The relatively small result of Variance Inflation Factor (VIF) (smaller than 10) shows that these independent va riables are not closely related to each other so there is no multicollinearity occuring. Table 5 of the coefficients analy sis shows the result of multiple regression analysis. Positive mark of regression coefficients show that components in the regression model above has positive relationship with customer satisfaction.
In terms of each component, Assurance component Sig. = 0.752 are greater than significant level 0.05, so all these components are not significantly effect on customer satisfaction. It means that we only accept two out of five hypotheses H4 and H5. Although 3 components: Reliability, Responsiveness, Empathy have no significant impact on the level of customer satisfaction, but these 3 components act as sufficient condition to establish the quality of the Bank service.

Discussion on the satisfaction of customers over the quality of ATM service in the Bank
Customer satisfaction with the Bank's ATM service was created by five quality components, which are Reliability, Responsiveness, Empathy, Assurance, and Tangibles. Results of the linear regression show that service delivery capacity and tangible utilities have significant influence on customer's satisfaction. It means that the higher assurance and tangibility are, the more satisfaction customers get. More specifically, in terms of assurance, customers highly appreciate the thorough knowledge about expertise and professionalism of banking officers in contact with custo mers, which requires the affability, courtesy and politeness, thus building up the trust and credibility for customers. Therefore, it can be seen that the Bank has staff with deep expertise and professionalism in providing customers with ATM service. The good human resources have brought the Bank the competitive advantage in providing ATM service. Besides, the level of security, confidentiality and utility in transactions are also chosen by customers as the criteria to demonstrate their satisfaction over ATM banking service of the Bank. Customers feel secure and committed to become longterm customers of the Bank.
Regarding tangibility, the quality of ATM card (nice design and suitable size), the equipment for transactions such as: alwaysclear computer display screen, convenient and easy identification of the teller (ATM machinery) are the factors that create satisfaction of customers over the service. Among them, quality criteria, appearance, design of cards are highly evaluated as they are appropriate for using in a dynamic and modern life. Furthermore, the display screen of machinery also affects the quality of service of the Bank. ATM machineries' screens of the Bank have high resolution, userfriendly and convenient window display for users, which create advantage for the quality of service of the Bank. Last but not least, customers highly appreciate the convenient, easilyidentified and highly secured place of ATM machinery in making transactions.

Recommendations for assurance
First and foremost, the Bank needs to constantly improve service quality to enhance customer satisfaction, especially improving the quality of human resources. It is important to have enough human resources and also improve the capa bilities of human resources. Customer caring staff must be knowledgeable, professional and equipped with soft skills i.e. communication skills and sales skills. Simultaneously, the bank staff should also have good service attitude, be polite, enthusiastic to meet customer's expectation and to shape positive behavior and attitude in customer service among their employees. The Bank continuously improves the level of modern banking technology. The technological capabilities and pe ople using that technology play a crucial role in the quality of customer service. Technology creates rapid advancement and enhances the ability to meet customer expectations. The trust and loyalty of customers depend on modern technolo gy, as well as the utility, value added services for customers.
Bank offices, especially where conducting transactions with customers should be decorated beautifully, have eye catching and harmonious color combinations, with easi ly recognizable and distinctive decorations against other banks. Headquarters should have a logo and slogan state ment in ensuring quality services. The staff uniform also creates a comfortable and friendly atmosphere for custo mers and makes customers more assured when having transactions with the bank.
The Bank should regularly communicate with custo mers. Exchanging information with customers plays an important role in understanding and meeting customer expectations. Information exchange can be carried out in various forms and can be implemented parallel to each other such as customer conference, advertising programs, promotion of products and services, survey of customer needs, and hotline set up etc. By doing these, banks transmit to customers information about products, services, handle customer requests and collect feedback as well as customer complaints related to banking activities. The bank also ne eds to store centralized data about customers to facilitate customer service.
Moreover, customer complaints should be considered as signal for the banks to continuously improve service quality. The research shows that customers often complain about certain types of errors. If these errors could be found out ti mely, recorded, and amended actions to be made promptly, the number of complaints would drop. It also translates to the fact that customer confidence and satisfaction are en hanced. Many bank employees, even managers are worried, scared and reluctant to handle customer complaints. It is common that they do not show enthusiasm upon recei ving complaints. This is a misconception because customer complaints not only provides an opportunity to rectify and improve service processes but also creates an opportunity to retain customers. In addition, it also limits the spread of information since dissatisfied customers would tell others about their dissatisfaction.
The Bank should build a base of regular and loyal custo mers. The loyal relationships of customers are reflected in longterm transaction relationships, the ability to increase the size and diversity of the transaction and the ability to persuade others to use the bank's services. Customer loyal ty increases profits through increased sales, reduce custo mer sensitivity to price, and reduce customer service costs because they are now familiar with the bank's operating system. To have a base of loyal customers, the bank should firstly start to build customer's trust & belief in bank ser vices and also ensure service quality provided by the bank. In addition, the attitude, professionalism and the ability to satisfy customer needs are important factors. Besides, it is not correct to assume that discount and promotion campaign are enough to attract and retain customers. These solutions only work in short term and can attract just a small number of random customers. However, they would fail to gain customer loyalty if these campaigns cannot ensure service quality of the bank.

Recommendations for tangibles
For transaction space, the Bank needs to estimate the future market development before choosing to open new tran saction locations in order to avoid circumstances such as if the Bank must upgrade or widen them only after a short time, which is wasteful and has negative influence on the psychology of customers when transactioning during time of construction. In addition, card division should be esta blished in each transaction location to give exact advice to the customers on the advantages and utility of using cards.
Regarding documents, leaflets on ATM service, the Bank should check the currently used leaflets to reject the ones with obsolete information, sketchy design or over lapping contents. It also should have professional design organizations consult about necessary contents and images to yield leaflets that can attract customers' care and atten tion. Especially, the Bank needs to design unique and fresh banners in promotion programs to advertise the sevice di rectly and lively.
In terms of ATM locations, while carrying out a survey and choosing locations to install ATMs, along with the cri teria of population density, traffic system, the Bank needs to carefully study security issues, especially parking place for the customers. To do this effectively, parking area should be included in the ATM room construction design, which is an important factor that helps customers feel comfortable and safe with their properties when conducting transactions.

Conclusion
Service quality plays a significant role in maintaining and developing sustainable competitive advantage of company or firm because service quality influence directly customer satisfaction. Thus, this study focused on investigating the relationship between service quality and customer satisfaction on ATM service of a private commercial bank in Vietnam by using SERVPERF model.
The research used 24 observed items divided into 5 com ponents of service quality and one component of customer satisfaction based on SERVPERF model. The number of respondents is 186 and these samples were tested by using SPSS software 16.0 through descriptive analysis, factor ana lysis and regression analysis. As a result, we found that two factors that have impacts on ATM service quality of the Bank, which are assurance and tangibles, in which assurrnce has the strongest effect on customer satisfaction.
Based on these findings, some recommendations for improving the ATM service quality of the Bank are raised in the upcoming time. In addition, the study results also have useful implication for other banks when making their service policy. This study provides more empirical evidence for academics on ATM service quality of commercial banks by using SERVPERF model.
The study made positive contribution to the bank in learning about factors affecting customer satisfaction about ATM service quality. However, this study also has the following limitations: firstly, the study was carried out on customers using the ATM service of the Bank so its generalization level is not high. Its generalization level would have been higher if this study had been carried out for some more banks in other cities in Vietnam, which is a direction for the next research. Secondly, this study only focuses on private customers with their own criteria to evaluate the service quality, so the study results cannot be right for all customers. This study should be additionally conducted on enterprise customers, thus we can genera lize customers satisfaction at ATM service quality. Finally, the study mainly considers the effects of quality factor on customer satisfaction at ATM service quality. There may be many other factors which affect customer satisfaction such as enterprise image, customer value, etc. This also suggests for further research.