The Effect of Brand Image and Quality Service on Saving Decisions with Competitive Advantage as an Intervening Variable at Bank DKI Mayor Branch, East Jakarta

Nowadays, business competition is getting more stringent, therefore a competitive strategy is needed that companies must have to survive in this business competition, especially banks in an effort to increase the number of customers. Therefore, this research was conducted to analyze the effect of brand image and quality service on saving decisions with competitive advantage as an intervening variable at Bank DKI Mayor Branch, East Jakarta. The population in this research is customers who open accounts at Bank DKI Mayor Branch, East Jakarta. The data collection method uses a survey method by filling out a questionnaire. Data analysis using the SEM (Structural Equation Modeling) software application with the AMOS program. The results of this research obtained the following results: (1) brand image has a positive and significant effect on purchasing decisions; (2) brand image has a positive and significant effect on competitive advantage; (3) service quality has a positive and significant effect on purchasing decisions; (4) service quality has a positive and significant effect on competitive advantage; and (5) purchasing decisions have a positive and significant effect on competitive advantage.


INTRODUCTION
Nowadays, business competition is getting more stringent, therefore a competitive strategy is needed that companies must have to survive in this business competition, especially banks in an effort to increase the number of customers. Lenggogeni and Ferdinand (2016) stated that brand image has an effect on purchasing decisions with competitive advantage as intervening. One of the companies engaged in financial services and actively providing good service and maintaining the brand image of its products is Bank DKI. Bank DKI is commercial bank whose shareholding is owned by the Provincial Government of DKI Jakarta of 99.98% and shares owned by Perumda Pasar Jaya of 0.02%. Bank DKI was established and operated since 1961 and the first BPD bank in Indonesia. Bank DKI provides various banking products and services that reach various segments of society and business fields. Bank DKI has 276 offices throughout Indonesia with details of 2 main branch offices, 14 branch offices, 229 sub-branch offices, 5 cash offices and 26 functional offices.
According to Montolalu & Raintung (2018) in their research, it is stated that the brand image variable has a significant effect on the purchasing decision variable. However, contrary to the research of Nandia & Nabila (2021) which states that the brand image variable has no effect on customer decisions to become a bank customer. Then, in previous research from Suprapto and Nafisah (2020) stated that quality service has an effect on purchasing decisions. However according to Pradita & Sitio (2020), quality service has no effect on purchasing decisions. There are several objectives of this research is analyzing the effect between brand image variables and competitive advantage, the relationship between service quality variables and competitive advantage, the relationship between brand image variables and purchasing decisions for savings products, the relationship between competitive advantage variables and purchasing decisions, the relationship between brand image and purchasing decisions, and the relationship between brand image and purchasing decisions.

Theory of Planned Behavior (TPB)
Theory of Planned Behavior (TPB) is a theory that explains a person's problems that cause a person to take certain actions. TPB can be used to explain a person's interests and behavior. Therefore, this theory is very appropriate to explain the desires and behavior of a consumer towards the company. TPB has three concepts, such as (1) attitude towards the behavior; (2) subjective norm; and (3) perceived behavior control.

Marketing Concept and Marketing Management
Marketing is the core of a business. There is no company without marketing, but the definition of marketing itself is still quite confusing. Meanwhile, according to Kotler and Amstrong (2015), marketing as the process by which companies create value for costumers and build strong customer relationship in order to capture value from customers in return. Management is often defined as a process of a series of planning, organizing, mobilizing and supervising activities conducted to achieve a predetermined target or goal. In addition, Kotler and Keller (2016) stated that marketing management as the art and science of choosing target markets and getting, keeping, and growing customers through creating, delivering, and communicating superior customer value.

Brand Image
Brand image is a consumer perception of a product brand that is formed from information obtained by consumers from their experience in using a product. Kotler and Keller stated that brand image is a customers' perception as represented in the associations that occur in the customer's consciousness. The brand image in the bank issue is shaping competitive advantage and customer decisions to save. These are several indicators that modified by the researchers itself, such as (1) competitive compared to other banks; (2) easy to find and large numbers; (3) trusted Regional Development Bank; (4) guaranteed deposit security; and (5) good interbank cooperation.

Quality Service
According to Kasmir (2016), quality service is the action of a person or organization that aims to provide satisfaction to customers or employees. If the service obtained is in accordance with the expectations of consumers, then the quality of service is perceived as good and can encourage consumers to make purchases and will become loyal customers. Kasmir also stated that there are 9 indicators of quality service, such as (1) having professional employees; (2) availability of good facilities and infrastructure; (3) availability of the desired product range; (4) being responsible to each customer from the beginning of the transaction to completion; (5) being able to serve quickly and precisely; (6) being able to communicate well and clearly; (7) guaranteeing confidentiality in every transaction; (8) having good knowledge and skills about the product; and (9) being able to provide trust to customers.

Competitive Advantage
According to Kotler and Amstrong (2015), competitive advantage is an advantage over competitors that is obtained by offering greater customer value with lower service quality or providing more benefits that justify higher service quality. Porter (2018) stated that there are 5 strategies that companies can do to overcome fierce competition to protect the company's market share, such as (1) change the policy of establishing service quality; (2) increase product differentiation; (3) find ways to use channel distribution more creatively; (4) utilize relationships with suppliers; and (5) improve service levels.

Purchasing Decision
According to Kotler and Armstrong (2015), purchasing decisions are the behavior of customers, both individuals, groups and organizations, choosing, buying, using a product such as goods, services, ideas or experiences in fulfilling consumer needs and desires. They also stated that purchasing decisions has 6 dimension, such as (1) choice of product; (2) choice of brand; (3) choice of supplier; (4) purchase time; (5) purchase amount; and (6) payment method. In addition, they argued that purchasing decisions has four types, these are (1) complex buying behavior; (2) dissonance-reducing buying behavior; (3) habitual buying behavior; (4) consumer purchasing behavior in situations in which consumer involvement is low and brand comparability is low; and (5) variety-seeking buying behavior.

RESEARCH METHODOLOGY
The research design used in this research is explanatory research. According to Sugiyono (2017), explanatory research is a research method that explains the position of the variables studied and the influence between one variable and another. The type of research used in this research is quantitative research. Sugiyono (2017) states that quantitative research methods can be interpreted as research methods based on the positivism philosophy. The variables that used by researchers consist of (1) independent variable being used by brand image (X1) and quality service (X2); (2) intervening variable being used by competitive advantage (Y); and (3) dependent variable being used by purchasing decisions (Z). According to Sugiyono (2017) population is a generalization area consisting of objects/subjects that have certain qualities and characteristics set by researchers to be studied and then concluded. The population in this research are all customers who open accounts at Bank DKI Mayor Branch, East Jakarta.
The sampling technique used is non probability sampling, namely quota sampling. Researchers provide sample limits with a minimum of 100 to 200 samples which will be distributed to respondents approximately 50 samples per week. According to Ferdinand (2014), the sample size that must be met in this modeling is a minimum of 100 and then uses a ratio of 5 observations for each estimated parameter. Sugiyono (2017) also states that primary sources are data that directly provide data to data collectors. Researchers provided questionnaires with the assistance of frontliners from Bank DKI Mayor Branch, East Jakarta. After obtaining and grouping these scores through a Likert scale, the results of the questionnaire answers were collected and analyzed using the SEM (Structural Equation Modeling) software application with the AMOS program.

Research Object Description
Bank DKI was established on April 11, 1961. Bank DKI offers various banking products and services that cover various segments of society and economy, such as the provision of foreign exchange services and the provision of sharia banking services since 1992. In realizing the vision and achieve the mission, Bank DKI decided to transform into a large corporation and center of excellence that emphasizes the excellence of Bank DKI through five main aspects i.e. performance, responsible corporate governance, human resources, services and corporate social responsibility.

Respondent Profile
In this research, the total respondents obtained were 195 people and grouped by gender, age, education, type of savings, and last education. In this research, the respondents used were customers who saved at Bank DKI Mayor Branch, East Jakarta.

The Respondents Result Data
According to the questionnaire results that have been filled in by the respondents, the researchers processed the data from each statement in the questionnaire and presented it in tabular form as follows:  Interpretation: High Source: Processed Data by Researchers (2023) The results of this research indicate that the respondents responded well to the brand image provided by customers of Bank DKI Mayor Branch, East Jakarta with an interpretation of 83.6 which indicates that they get a high interpretation.  Average Score 75,9 Interpretation: High Source: Processed Data by Researchers (2023) The results of the research indicate that the respondents responded well to the quality service provided by customers of Bank DKI Mayor Branch, East Jakarta with an interpretation of 75.9 which means getting a high interpretation.  Average Score 80,3 Interpretation: High Source: Processed Data by Researchers (2023) The results indicated that the respondents responded well to the purchasing decisions made by Bank DKI Mayor Branch, East Jakarta customers with an interpretation of 80.3 which means getting a high interpretation.  Average Score 80,3 Interpretation: High Source: Processed Data by Researchers (2023) The results showed that the respondents responded well to the competitive advantages provided by Bank DKI Mayor Branch, East Jakarta customers with an interpretation of 82.9 which means getting a high interpretation. This structural model is marginal fit overall, such as Prob, RMSEA, GFI, TLI and CFI, Chi-quare and AGFI, only CMIN/DF fulfills the criteria. In addition in conducting confirmatory tests on all variables, it is obtained that all variable construct indicators have a probability value of p < 0.05 and also comply with the convergent validity value. It can be inferred that all data in the full model diagram is valid.

Goodness of Fit Test
Goodness of Fit Test (GOF) testing is conducted to determine the fit of the model with the data obtained which will be used as a reference that whether the structural equation model is acceptable or not. The following is a summary of the GOF test results which can be seen in the table below:  (2023) Chi Square X2 in this research is 683.288, with a probability of 0.192. The CMIN/DF results indicate a marginal fit model evaluation because it fulfills the cutt of value. While the results of RMSEA, GFI, AGFI, TLI and CFI, indicate a marginal fit model evaluation because it is almost approaching the cutt of value.  (2023) The C.R values all qualified as <1.96 at a significance level of 0.05, so it can be accepted because the causal relationship of the variables is qualified (>1.96) at a significant level (p-value) of <0.05. Hypothesis Assumptions Description: Ho = Brand image has no effect on purchasing decisions. Ha = Brand image affects purchasing decisions.

The Effect of Brand Image on Purchasing Decisions
The results indicate a C.R value of 3.255> 1.96 at a significant level (p-value) of 0.001 <0.05 so it can be concluded that Ha is accepted, which means that brand image has an effect on purchasing decisions. Hypothesis Assumptions Description: Ho = Brand image has no effect on competitive advantage. Ha = Brand image affects competitive advantage.

The Effect of Brand Image on Competitive Advantage
The results indicate a C.R value of 2.022> 1.96 at a significant level (p-value) of 0.043 <0.05 so it can be concluded that Ha is accepted, which means that brand image has an effect on competitive advantage. Hypothesis Assumptions Description: Ho = Quality service has no effect on purchasing decisions. Ha = Quality service affects purchasing decisions.

The Effect of Quality Service on Purchasing Decisions
The results indicate a C.R value of 4.891> 1.96 at a significant level (p-value) of ***<0.05 so it can be concluded that Ha is accepted, which means that quality service has an effect on purchasing decisions. Hypothesis Assumptions Description: Ho = Quality service has no effect on competitive advantage. Ha = Quality service affects competitive advantage.

The Effect of Quality Service on Competitive Advantage
The results indicate a C.R value of 1.957=1.96 at a significant level (p-value) of 0.05=0.05 so it can be concluded that Ha is accepted, which means that quality service has an effect on competitive advantage. Hypothesis Assumptions Description: Ho = Purchasing decisions has no effect on competitive advantage. Ha = Purchasing decisions affects competitive advantage.

The Effect of Purchasing Decisions on Competitive Advantage
The results indicate a C.R value of 2.530 >1.96 at a significant level (p-value) of 0.011<0.05 so it can be concluded that Ha is accepted, which means that purchasing decisions has an effect on competitive advantage. Hypothesis Assumptions Description: Ho = Competitive advantage has no effect on purchasing decisions. Ha = Competitive advantage affects purchasing decisions.

The Effect of Competitive Advantage on Purchasing Decisions
The results indicate a C.R value of 1.960 = 1.96 at a significant level (p-value) of 0.050 = 0.05. Therefore, it can be concluded that Ha is accepted, which means that competitive advantage has an effect on purchasing decisions. Hypothesis Assumptions Description: Ho = Brand image has no effect on purchasing decisions mediated by competitive advantage. Ha = Brand image affects purchasing decisions mediated by competitive advantage.

The Effect of Brand Image on Purchasing Decisions mediated by Competitive Advantage
The results of this research indicate a C.R value of 6.218, 3.077, and 2.937> 1.96 at a significant level (p-value) of 0.000, 0.002, and 0.003 <0.05, therefore it can be concluded that Ha is accepted, which means that brand image has an effect on purchasing decisions mediated by competitive advantage. Hypothesis Assumptions Description: Ho = Quality service has no effect on purchasing decisions mediated by competitive advantage. Ha = Quality service affects purchasing decisions mediated by competitive advantage.

The Effect of Quality Service on Purchasing Decisions mediated by Competitive Advantage
The results indicated a C.R value of 5.904, 2.469, and 3.125> 1.96 at a significant level (p-value) of 0.000, 0.014, and 0.002 <0.05 so it can be concluded that Ha is accepted, which means that quality service affects purchasing decisions mediated by competitive advantage.

The Research Discussion Brand Image on Purchasing Decisions
The results indicate that brand image has a positive effect on purchasing decisions at the 0.05 significance level. This indicates that this research supports previous research conducted by Zamroni (2016), brand image variables and promotions have a partially significant effect on purchasing decisions.

Brand Image on Competitive Advantage
The results indicate that brand image has a positive effect on competitive advantage at the 0.05 significance level. This indicates that this research supports previous research conducted by Chaerudin & Syafarudin (2021), brand image has a positive and significant effect on the competitive advantage of consumers of medical device products owned, service quality is proven to have a positive and significant effect on the competitive advantage of consumers of medical device products, service quality is proven to have a positive and significant effect on the competitive advantage of consumers of medical device products.

Quality Service on Purchasing Decisions
The results indicate that quality service has a positive effect on purchasing decisions at the 0.05 significance level. This indicates that this study supports previous research conducted by Budiono (2020), which simultaneously affects service quality, promotion, and brand image on purchasing decisions.

Quality Service on Competitive Advantage
The results indicate that service quality affects competitive advantage at the 0.05 significance level. This indicates that this research supports previous research conducted by Tirtayasa et al (2022), partially brand image has a significant effect on customer competitive advantage, service quality has a significant effect on customer competitive advantage.

Purchasing Decisions on Competitive Advantage
The results indicate that competitive advantage has a positive effect on loyalty at the 0.05 significance level. This indicates that this research supports previous research conducted by Ilham et al (2020), purchasing decisions have a positive relationship and have a significant effect on customer competitive advantage.

Conclusion
According to this research, brand image affect customer decisions in a positive and significant impact. Brand image has a positive and considerable impact on competitive advantage in this research. In this research, customer service quality affects purchases in a positive and significant form. The findings of this research, the level of service has a positive and considerable effect on competitive advantage. Purchases had a positive and significant impact on competitive advantage in this research.
In order to enhance service excellence, Bank DKI can open several branch offices at the sub-district level to minimize the accumulation of queues. In addition, it can increase the opening of branch offices outside the region so that Bank DKI can expand branding, to make it more recognized by many people. Bank DKI can also expand advertising with videotrons in order to increase its competitive advantage with other banks.
The quality service provided is very good but still needs to be improved so that it can compete with other banks. Regarding the quality service of frontliners in terms of service to customers, being able to provide problem solving needs to be improved by doing roleplay regularly, product knowledge understanding tests with materials that contain knowledge of new things and economic conditions that are going on outside so that they can build broad communication with customers.

Suggestion
The company is expected to continue to maintain and improve its brand image continuously in order to create a distinct advantage over similar competing brand products. The second suggestion should offer service quality that matches the brand image provided by the product. It means that if the quality of service is improved, the resulting brand image will also increase. The most important thing is that the quality of service offered is greater than the quality of service announced by competitors so that their products can always compete with other competitors.

The Limitation of Research
This research has been conducted in accordance with scientific procedures, however, it still has limitations, such as (1) the factors that affect saving decisions in this research only consist of two variables, which are brand image and quality service, while there are still many other factors that affect saving decisions; and (2) there are limitations to research using questionnaires which during the process of filling out questionnaires, researchers cannot directly control respondents in which researchers use google form.