Alliance Management Practices for Higher Trust, Commitment and Inter-Organizational Relationship Performance: Evidence from Travel Companies in Vietnam

: Vietnam tourism experienced impressive growth from 2008–2019, but it has weakened due to the impact of the pandemic up to the present. So, what should the travel companies and their partners do to overcome the crisis caused by the COVID-19 pandemic? This paper aims to identify what alliance management practices (AMP) factors help improve the inter-organizational relationship performance (IORP) between travel companies and their partners through the mediating roles of trust and commitment. A quantitative approach was applied with data collection from representatives of 319 SMEs of travel companies and the PLS-SEM was used to test the hypotheses. The ﬁndings indicated that trust, commitment, coordination, and frequency of interaction directly affect IORP, and simultaneously, communication and participation have indirect impacts on IORP. This study provides suggestions for all tourism companies to be aware of the need to form relationships with other partners to sustainably survive and develop together.


Introduction
At present, Vietnam is well-known as a favored destination with its naturally delicate richness. There are a lot of enormous natural caves and incredible bays that UNESCO has recognized as "World Natural Heritage Areas", and Vietnam has many types of tours for travelers, for example, "cultural and historical tours, sea-based tours, adventure tours, eco-tours, and luxurious vacations" [1]. Thanks to the gifts from Mother Nature, Vietnam's tourism industry has made remarkable achievements in terms of tourism revenue in recent years; the total revenue is accounted for USD 26.66 billion and USD 32.47 billion from 2018 to 2019 [2], and the rate of international tourists has increased from 5 million visitors to 18 million from 2010 to 2019 [3,4]. However, in 2020 the COVID-19 pandemic caused Vietnam's tourism industry to plunge when a series of accommodation establishments, restaurants, tourist attractions, and travel companies were lost. These tourism sectors must suspend operations and wait for the end of the pandemic. About 10% of activities are held in moderation to keep operating to handle debts with partners and customers and all employees are working online at home, took unpaid leave, or terminated their labor contracts. In addition, 100% of tour guides were forced to quit their jobs. Many hotels offered employees full breaks, stopped doing business, and put their properties up for sale. Transportation companies and entertainment areas such as amusement parks also had to suspend operations because there were no visitors [5]. The pandemic has wholly crippled the Vietnamese tourism industry. So, all tourism sectors must stand together to achieve mutual goals to overcome the pandemic. Hodge et al. [6] stated that an organization might form relationships with other organizations to reduce uncertainty and analysis and then the findings and discussions. Finally, part six provides conclusions and limitations.

Alliance Perspectives
Alliances are described as "an arrangement between two or more firms that establishes an exchange relationship but has no joint ownership involved" [18]. According to Oliver [19], the firms with some level of interdependence form alliances for establishing stable relationships and expected capability streams. Alliance may be based on different forms such as "joint ventures, franchising, long-term marketing, and licensing contracts, reciprocal trade agreements, R&D partnerships, and affiliation in research consortia" [20]. Additionally, Chen et al. [21] suggested that "a strategic alliance is a formal agreement between two or more business organizations to pursue a set of private and common interests through the sharing of resources in contexts involving uncertainty over outcomes" [21]. Strategic alliances are long-term exchanges, but it appears to be a temporary interface in nature, in which members of organizations participate to achieve their respective goals together. The cooperation between the parties is to integrate each other's resources to achieve mutual goals which a company cannot accomplish independently. The alliance members must possess additional resources to obtain this combined power. The success of an inter-organizational relationship is related to the alliance management practices that can provide additional resources and economic motivations [21,22]. Alliance management practices may help inter-organizational communication succeed, such as appropriate and timely sharing of meaningful information and coordination among firms. The precise specification of roles and execution of tasks, avoiding errors, planning and scheduling for products, and frequent meetings and discussions of all issues shape the highest trust in the alliances in ways that foster trust, such as believing that our partners always do the right things for the relationships to reduce uncertainty resulting from opportunism [12,14,23].

Inter-Organizational Relationship Performance (IORP)
An inter-organizational relationship exists when two or more firms exchange resources such as monetary resources, materials, services, products, physical facilities, guests, referrals, employees, etc. The rational inter-organizational relationships occur temporarily or in the long term [24]. The organizations come together to overcome resource scarcity and share risks with their partners, motivating SMEs of travel companies to cooperate with others that they believe can achieve mutual goals effectively. The IORP was defined as the overall satisfaction with the performance expectations and mutual performance so that the higher inter-organizational relationship performance will be greater [8,25]. IORP refers to the overall satisfaction focus on the positive experiences of organizations based on obeying policies and rules and carrying out performance expectations with all participants in the relationship [26]. Morgan and Hunt [12] studied the impact of IORP and found that trust and commitment play mediating variables. These crucial roles of the development process in IORP, i.e., trust and commitment, identify the partnership achievement to build up productivity, capability, and performance [9][10][11]13]. After joining the relationships with partners, the focal firms define that their partners are the excellent firms to do business with and lead to more "productive and grown up a lot" [8], and "feel more powerful and confident" [17]. In addition, Palmatier et al. [9] had discovered that trust and commitment can have a positive, direct, and indirect effect on inter-organizational relationship performance and stated that IORP based on "the increase total sales, cooperation, trust in a high degree of harmony, always do the right things, benefit expectations and capability to implement the objectives, had high integrity" [10,11]. Furthermore, Mouzas et al. [27] discovered that the organizations built up IORs based on the benefits expectations and capability to implement the objectives from partners [11,28]. In addition, the primary motivation to set up the IOR is to receive benefits from their partners, such as a study of inter-organizational performance [29] focus on profitability, achieving a high sales target, and a high income growth. A great deal of previous research into IORP has found different antecedents' effects on inter-organizational relationship performance. In addition, Mohr and Spekman [7] conducted empirical research exploring the characteristics of partnership success and proposed that a combination of coordination, trust, commitment, communication, and participation was highly associated with relationship success. Especially, a study in relationships' success by Medina-Munoz and Garcia-Falcon [8] discovered that commitment, coordination, participation, communication quality, and trust were positively associated with overall successful relationships.

Inter-Organizational Communication
Regarding a perspective directly related to human behavior, communication is a process through which "the information is exchanged and understood by two or more people" [30,31]. The perspective of inter-organizational attitude shows that communication was considered a variable impact on the quality of interrelationships [30,32]. Interorganizational communication is the glue and maintains the relationships [33], which sends open and diverse information to other organizations through communication channels of the relationships to the partners [7,33,34]. Other studies have assessed that the efficacy of inter-organizational communication must be especially timely and transparent among partners [35]. Commenting on inter-organizational communication, Turker [30] defined it as the sharing of the "formal and informal about the meaningful information and timely information among firms", which takes on a significant role and affects the relationship performance [22,26]. Past communication is treated as an antecedent to trust and builds trust over time and enhances communication. The scholars found that communication behavior such as quality communication and information sharing influences relationship success [8], and the empirical study produced significant statistics. As Paulraj et al. [36] defined, inter-organizational communication is sharing reliable information, providing information that might help partners, and exchanging information frequently, informally, or promptly. Furthermore, Moscardo [37] found that elements of communication include communication source credibility, trustworthiness, and ease of comprehension. Similarly, Palmatier et al. [38] pointed out that "the inter-organizational communication is the amount, frequency, and quality of information" that was shared among partners. Their findings showed that the communication antecedent had a significant and positive influence on trust and commitment [12]. Morgan and Hunt [12] pointed out that communication had significant positive effects on trust [9,12] and communication had significant positive effects on commitment [10,13]; moreover, communication indirectly affects commitment through trust, and communication directly affects IORP [7]. These findings were confirmed by Palmatier et al. [38], who stated that the antecedent of communication has the most significant influence on relational mediating of trust and commitment. Their findings showed that communication had significant positive effects on relational mediating of trust and commitment.

Inter-Organizational Coordination
According to Narus and Anderson [39], inter-organizational coordination is a policy in which the members in the IOR seek to work in cooperation in the great effort, which depends on a set of duties and responsibilities that each party looks forward to partner completed [12]. Similarly, Palmatier et al. [38] pointed out that coordination combined and integral activities among exchange partners to reach associated targets such as arrangement and joint actions [18]. Similar work has also been pursued by others [7], in which coordination showed better successful partnerships accompanied by high levels of coordination. Their test was significant and affected partnership successes directly. In the oncological context, Flieger et al. [40] suggested that inter-organizational coordination involves using strategy and behavior characteristics to integrate and align activities, knowledge, and purposes of interdependent members to achieve the mutual goals in the relationships [41]. Medina-Munoz and Garcia-Falcon [8] proposed that the primary measure of IORP is based on well-coordinated activities with the partners; in addition to this relationship, success must have a clear plan and schedule for product's delivery with partners. Their findings showed that there was a positive influence between coordination and overall successful relationships. Coordination refers to "the boundary definition and reflects the set of tasks each party expects the other to perform" [7,17]. According to Salancik and Pfeffer [17], "the stability in an uncertain environment can be achieved via greater coordination lead to success in IORP". Furthermore, Mohr and Spekman [7] found that the relationship between coordination and successful partnerships was significant. In addition, Medina-Munoz and Garcia-Falcon [9] found that there was a positive influence between coordination and overall successful relationships. From this viewpoint, coordination influences the degree of trust and commitment [7,26,38].

Flexibility
Much of the literature on flexibility in the context of alliances has not mentioned flexibility in managing the relationship but have instead talked about entering and exiting particular commitments in light of changing circumstances [42][43][44]. As Gibson et al. [45] noted, flexibility is defined as the degree to which partners respond to requests for changing circumstances [46]. Furthermore, Aulakh and Madhok [22] have proposed that flexibility was strongly associated with relationship effectiveness. Flexibility in accommodating one another's needs, preferences, and opinions, especially in dynamic environments, provides the glue for a smoother and more stable relationship. The flexibility results in "greater adaptability to changing circumstances and reduces the likelihood of the relationship becoming asynchronous with the environment." Moreover, a more flexible relationship is also more "sticky" rather than rupturing or resorting to costly contractual mechanisms in the case of conflict. As a result, the relationship is more resilient to the normal ebbs and flows that characterize inter-firm collaboration. Differently put, there is a more significant "band of tolerance" characterizing the relationship that enables the partners to ride out temporary periods of inequity [47] and to continue to engage in the mutual "give and take or reciprocity" that undergirds any successful relationship. Thus, it reduces the cost associated with governing the partnership and enhances the value attained through flexibility [48,49]. Similarly, Dahistrom et al. [50] defined that flexibility refers to carrying out the requests for changing that is a characteristic of this relationship and the exchange of information, which can support their partners. In addition, such flexibility happens informally and frequently based on the specific agreement and supplies the partners' unique information. Trust indicates improved flexibility, as observed in [22,51], and their results found that flexibility positively affected trust and influenced partnership performance. These findings were confirmed by Dyer and Chu [52]. Alliance performance is influenced by flexibility, which enhances performance in alliances [50].

Frequency of Interaction
According to Christopher [53], interaction frequency is considered the central aspect of communication and information sharing. The frequency of interaction refers to the level of IOR based on "the frequency of interactions often among organizations might contribute to the development of long-standing and valuable relations." In addition, the frequency of interaction increases the degree of participation in the relationship [30,54]. According to Williamson [16], the increase in transaction regularity prepares the more incredible inter-organizational performance, because the frequency of transaction help to recovery of costs of functional organization arrangements, such as "comprehensive purchase contracting, repeat contracts." The frequency of interaction refers to helping each other to minimize transaction costs, such as "expenditures for searching guests, enforcing contracts, and monitoring contracts." As Williamson [16] claims, "the overall goal is for an organization to seek the lowest cost; highest benefit IOR alternatives." Moreover, the frequency of interaction is requesting information or giving/sending information [54]. Similarly, Turker [30] showed that the relationship between interaction frequency and trust affected the power of relational sources by other organizations. As Schmidt and Kochan [55] analyze, "the nature of interaction in symmetric and asymmetrical relations from the integrated perspective of exchange and power-dependency approaches," suggesting that "the inter-organizational partnerships was a mixed-motive situation in which each organization behaves under its self-interests". To survive well in an uncertain environment, the organizations should maintain relationships and frequently keep in touch with other organizations to supply resources [30]. Similarly, Palmatier et al. [38] found the relationship between interaction frequency and trust and commitment, and the findings showed that interaction frequency has notably minor effects on trust and commitment.

Participation
Devlin and Bleackley [56] defined participation as the levels at which co-workers mutually participate in setting goals and planning schedules. When one party's activities impact the ability to compete effectively with other parties, so the need for participation to ensure specific roles, duties, and responsibilities was implemented, and of course, the confidence increases in this relationship [7,8,57]. Similarly, Anderson et al. [58] noted that "the input to decisions and goal formulation" were significant features of cooperation and participation, which lead to the success of partnerships. A large and growing body of literature has explored the relationship between participation and IORP, trust, and commitment. For example, Driscoll [59] also observed that participation in decision making was positively associated with satisfaction in this relationship. He has explored the relationships between participation and inter-organizational trust showed that the participation in collaborative planning grants given and taken trust to be established and coordinated efforts to be specified.
Moreover, participation relates to how the partners participate in decision making. Deetz [60] proposed that decision making includes a procedure system, planning, authorization, engagement, and attendance. However, other scholars have underlined that the most crucial element of decision making is the relevant equal participation to reconstruct doing business with partners. It showed the participation could permit the partners to debate their interests in the associated decision-making system [30,60]. The participation showed the degree of the attendance of sharing the vital information when it exhibits the high levels of communication character, sharing helpful information, participation in planning, and goal setting that led to successful partnerships [7,8], and they found that there was positive significant difference influence between participation and overall successful relationships. The results indicated that high degrees of participation in decision making lead to successful partnerships.

Inter-Organizational Trust
The research defines inter-organizational trust as "the mutual trust refers to the confidence that each party will fulfill its obligations and behave as expected" [28,51]. Interorganizational trust based on reliance built upon two objective principles was benefit expectations and capability to implement the objectives from partners [11,27,28]. Another perspective about inter-organizational trust, such as it did not appear quickly, came from building the relationship gradually and frequently over time and following a system of interactions [61]. Inter-organizational trust happened based on the familiarity with tourism sectors and past activities by knowing the precise capability of the partners such as their fame, knowledge, information, competence, goodwill, intentions, and strategy when doing business, which show the critical role in the first step of having the relationship with a partner by previous experience [11][12][13]38]. In the Taiwanese context, Yeh et al. [62] highlighted three indicators measure of relationship trusts such as honesty, trustworthiness, and task fulfilment. The relationship trust is known to represent an existence between interpersonal and organizations. If trust was increased and strengthened between people of the organization, it also leads to strengthening the connections between members and the organization. It also speeds up the formation of trust between members. In addition, Mariño-Romero et al. [63] highlighted six items to measure of trust: honesty, keeping promises, feeling a sense of security, offering quality services and guarantees, and being interested in the customers since trust is required for developing the long-term relationships between organizations and customers.
Based on prior experience, organizations choose or refuse to cooperate with partners [64,65]. As Williamson [16] explored, inter-organizational trust is based on formal contracts as a system for reducing opportunistic behaviour that will not appear in the relationship if trust is established first. Similarly, a systematic literature review from 1990 to 2003 by Seppanen et al. [66] showed that "mutual trust is a key factor of relationship quality and performance with its impact on reducing the perception of risk, transaction costs, opportunistic behaviour and increasing effectiveness and cooperation among actors" [30]. This idea is also evident in Zucker's [67] work, which showed that contracts and commitments are the logical base for inter-organizational trust. In the empirical work published in [8], trust was described as the belief in a party's word to accomplish and implement their duties, and from this leads more developments in cooperation [26] and a belief that their partners always do the right things for the relationship since trust exists. Furthermore, inter-organizational trust has been proven to raise coordination, raise flexibility, decrease the costs of coordinating activities, and improve the degree of knowledge transfer [15,51,52]. Therefore, trust is supposed to have a positive, direct, and indirect effect on commitment and IORP.

Commitment towards the Relationship
Travel companies in inter-organizational relationships must depend on other partners' activities and external resources. So, the travel companies develop alliance strategies and interdependencies to share risks, resources, monitoring, and control; thus, the interorganizational commitment is established in this relationship [8]. Commitment refers to the partners' willingness to effort and desire to develop the relationship [7,68] and to be willing to make sacrifices and underline intentions to maintain the relationship [11,34]. Another concept of commitment by Jap and Ganesan [69] refers to the expectations that the parties would like to establish an ongoing relationship by being willing to sacrifice the short-term benefits to keep sustainably developing these relationships based on trust with partners. Commitment towards the relationship refers to having dedicated enough resources to maintain the relationships with partners who have performed the effectiveness, development, contracting, and standardizing of the commitment [9,11,12]. In the organizations, to have a high commitment was placed in front-class, and all parties managed to reach their goals and performed these objectives without the shadow of opportunism [70,71]. In the context of online shopping in China, Chen et al. [72] defined commitment as the exchange that partners believe in within the ongoing relationships with other partners, which is very significant to ensure that the maximum effort to maintain these relationships is being made, and they highlighted that the elements of commitment also include calculative commitment and affective commitment. Furthermore, Williamson [70] posits a transaction cost theory and points out that IOR among partners will appear as latent costs related to opportunism. So, the alliances were formed to reduce the uncertain environment, and the firm's competitive environment was stabilized by forming mutual expectations and norms of reciprocity to establish the commitment and regulate exchange transactions [73]. Other studies confirmed that the high levels of commitment and trust were related to greater partnership success. Their findings positively affected successful partnerships [9,12]. In addition, Medina-Munoz and Garcia-Falcon [8] found a positive influence between commitment and inter-organizational relationship performance [9,12].
From the above discussion of factors of AMP (communication, coordination, flexibility, frequency of interaction, and participation), we postulated the following hypotheses:

Measurement of Constructs
The quantitative survey tool was a structured questionnaire that was built based on scales related to this study. The scales were employed from the existing literature review to measure the constructs of this research and were modified to fit in our research context. There were three parts to the questionnaire: demographic of the respondents, independent variables of AMP (communication, coordination, participation, frequency of interaction, flexibility), and dependent variables (IORP, trust, commitment). We used a 5-point Likert scale to evaluate all questions ranged from "strongly disagree" to "strongly agree". Except for the question "How often does your company frequently interact with partners?" the Likert scales ranged from "1 = not at all" to "5 = very often". The scales evaluating the AMP (communication, coordination, participation, frequency of interaction, flexibility) were adapted from [7][8][9]12,22,43,51,54,55]. The scales for IORP were developed for this study based on [6,9,10,13,[16][17][18]. The scales for trust and commitment were adapted from [7,[9][10][11][12][13]18,20,24,37].

Data Collection and the Sample
Department of Tourism of Ho Chi Minh City announced that 90-95% of travel companies and tourism sectors have suspended operations; only a few still operate to handle debts with partners and customers, and employees are working online from home or took unpaid leave [5]. Data collection was conducted during the COVID-19 pandemic from December 2019 to December 2020 at travel companies in Vietnam. Data were collected in two ways: first, surveys sent directly to the travel companies, and second, survery links indirectly sent to respondents by email, Zalo app, Viber app, and online self-administered surveys available through Google Forms. Before sending surveys to the participants, we made a phone call or sent an email to invite the respondent to participate in this study with the following criteria: first, the travel companies have participated in inter-organizational relationships with tourism partners; second, the participants must be managers, vice managers, manager or vice-manager of marketing, or senior executives. These people were viewed as the best-qualified samples to provide information about the relationship with their partners (e.g., transportation companies, attractive destinations, accommodations, restaurants, and bars and historical, entertainment, and cultural-social events). Third, the tourism firms must be located in Vietnam. The sample size of this research was based on [74], suggesting that the sample size must be at least five times the observed variables. This study has 36 observed variables, so the minimum sample size is 5 × 36 = 180 surveys of the travel companies. The final valid data were 319 SMEs, which is expected to be an adequate response rate.

Statistical Methods
In this study, we used the PLS-SEM with Smart-PLS software version 3.0 to test the research hypotheses. Hair et al. [75] stated that the partial least squares technique was employed to explore the main predictions-the nature of the research and investigate the complex structural relationships among constructs. For the data analysis, there is a two-step approach to use in this current study based on the suggestion of [76]. The first step was the measurement model analysis to check the construct's reliability and validity by testing the factor loadings, composite reliability, and average variance extracted [77,78]. The second step evaluated the structural equation model to check the correlation among the latent constructs [79,80].

Sample Characteristics
As the descriptive analysis, the travel companies were established less than 2 years (9.4%), more than 2-5 years (33.2%), more than 5-10 years (37.6%), and more than 10 years (19.7%). Over half of the job positions were categorized in the senior sales, marketing, and market development departments (54.2%), the chief of the sales, marketing, and market development department made up 19.1%, 9/1% of respondents were the deputy director of their company, and finally, 8.8% were the director and deputy chief of sales, marketing, and market development departments. For the company locations, over half of those surveyed indicated that they came from the southern provinces of Vietnam (60.5%), and the rest were located in the central region provinces of Vietnam (39.5%). In terms of length of inter-organizational partnerships, 13.2% were in partnerships for less than two years, 37.9% from 2-5 years, 33.2% from 5-10 years, and 15.7% more than 10 years. Regarding the company's size, more than 50.2% had 10 to 50 employees, and 35.7% had less than ten employees. Only 8.2% had more than 100 employees. The most minuscule (6.0%) had 51 to 100 employees. Therefore, based on the companies' size, small and medium enterprises (SMEs) belong to the company (see Table 1).

Measurement Model Results
To measure all constructs of the research model, we analyzed the reliability and validity of the constructs. The first step was an evaluation of the reliability for the scales by using composite reliability (CR) may be a priority to measure the reliability. According to Hair et al. [75], the CR should be equal to or more significant than 0.06 to be considered acceptable, and the results from Table 2 demonstrate that the composite reliability of all the constructs in this study ranged from 0.868 to 0.910, which is suitable with the suggestions by [75]. Thus, the results indicated that all constructs in this study reflect the model of high levels of internal consistency reliability. The second step used the Average Variance Extracted (AVE) to evaluate the convergent validity and the divergent validity. At the level of the indices, based on the recommendation of [81], which provided the criteria and cross-loadings, the square root of the separate construct of AVE should be more significant than 0.5 that was acceptable at the level of convergent validity [75,81,82]. In our study, the AVE were all above the 0.5 threshold, ranging from 0.626 to 0.689 (see Table 1) and were thus suitable with the rules of thumb for model evaluation by [75]. Thus, the findings confirmed that all constructs were an adequate model [81]. To evaluate the discriminant validity, the Fornell-Larcker criterion suggestes that "an indicator's loadings should be higher than all of its cross-loadings" [81]. As such, the outer loadings of the factor loadings should be larger than 0.7 [83]. According to Hair et al. [75], "the AVE of each latent construct should be higher than the construct's highest squared correlation with any other latent construct." The discriminant validity results ranged from 0.791 to 0.830; all items were suitable with all constructs as shown in Table 3; among factors of alliance management practice, the IORP was the highest adopted by the travel companies (mean = 3.799). The flexibility was used in uncertain environments and was the second most adopted construct by the travel companies (mean = 3.984). The commitment towards the relationship also had high adoption from travel companies (mean = 3.971). The communication (mean = 3.889), trust (mean = 3.800), participation (mean = 3.799), frequency of interaction (mean = 3.840), and coordination (mean = 3.780) were absolutely high and all met the level of agreement from 319 travel companies.

Structural Model Assessment
The measurement model offered satisfactory results. The next step was the structural equation model that was determined to explain the target endogenous variable variance (trust, commitment, IORP). Finally, to predict the model's power was estimated, the R 2 weight of endogenous constructs was valued. As Chin [84] suggested, the endogenous constructs were analyzed by the model, represented on the variance.
Another tool to measure the model's fit is the predictive relevance evaluation measure built up by [85,86]. To predict the clarity indicators of hidden constructs based on crossvalidated redundancy (Q 2 value) built by [85,86], the Q 2 value was counted to determine the predictive relevance for the construct based on a blindfolding technique implemented in the partial least squares (PLS) technique. Concerning the recommendations of [84,87], the model shows the predictive relevance in the case that the Q 2 value is more extensive than zero for an endogenous variable to exhibit an acceptable fit. In this study, the average cross-validated redundancy achieved 0.402 for commitment, 0.429 for IORP, and 0.366 for trust, which was higher than zero. Therefore, there was a high predictive relevance for commitment, IORP, and trust to exhibit a good fit. This research-based on "nonparametric bootstrapping"-was built by [87], with 1000 replications to test the structural model and at the level of confidence interval 97.5%. Table 4 shows the results of the structural model from the Smart-PLS analysis.  Table 4 presents the findings of all hypotheses. Hypothesis one (H1) was tested, and the results were found that commitment (COMIT) had a positive and direct effect on three important factors (COMU, CORD, PART) at a 95% confidence level. The largest influence was COMU (β = 0.193, p = 0.014), followed by CORD (β = 0.173, p = 0.039), then PART (β = 0.165, p = 0.014). The findings indicated that for every standard deviation change in communication, participation, and coordination, there would be an increase of 0.193, 0.165, and 0.173 standard deviations in commitment, respectively. Our study empirically found that H1 was partially supported with H1a, H1b, and H1e. However, except for FLEX and FREQ, there were no significant direct effects on COMIT. Therefore, hypotheses H1c and H1d did not receive support (see Table 4). Furthermore, the coefficient of determination R 2 was 0.626 for commitment which means the flexibility, coordination, communication, participation, and frequency of interaction substantially explain 62.6% of the variance in commitment.
Hypothesis 2 was tested, and the results found that TRUST had a positive and direct effect on three important factors (COMU, CORD, PART) at 95% and 99% confidence levels. The highest influence COMU (β = 0.306, p = 0.000), followed by CORD (β = 0.160, p = 0.038) and finally PART (β = 0.269, p = 0.001). The findings indicated that for every standard deviation change in COMU, PART, and CORD, there would be an increase of 0.306, 0.269, and 0.160 standard deviations in TRUST, respectively. Hypothesis H2 was partially confirmed with H2a, H2b, and H2e. However, FLEX and FREQ were not significant effects direct on TRUST. Therefore, hypotheses H2c and H2d were rejected. Furthermore, the coefficient of determination R 2 was 0.576 for TRUST, which indicates that flexibility, coordination, communication, participation, and frequency of interaction moderately explain the 57.6% of the variance in TRUST.
Hypothesis 3 was tested, and the results found that COMIT had a positive and direct effect on TRUST at a 99% confidence level. It was the highest influence with COMIT from TRUST (β = 0.255, p = 0.000). These findings indicated that every standard deviation change in TRUST would change by an increase of 0.255 standard deviations in COMIT, so H3 was confirmed.
Hypothesis 4 was tested, and the results found that IORP positively affected four important factors (COMIT, CORD, TRUST, FREQ) at a 99% confidence level. The greatest impact on IORP was COMIT (β = 0.400, p = 0.000), followed by CORD (β = 0.205, p = 0.010), TRUST (β = 0.179, p = 0.004), and FREQ (β = 0.171, p = 0.000). The findings indicated that for every standard deviation change in COMIT, CORD, TRUST, and FREQ, there would be an increase of 0.400, 0.205, 0.179, and 0.171 in the standard deviations in IORP, respectively. Thus, Hypothesis 4 was partially supported with H4a, H4c, H4e, and H4g. However, COMU, FLEX, and PART had no significantly different impact on IORP. Therefore, hypotheses H4b, H4d, and H4f were rejected. Furthermore, the findings showed that the coefficient of determination R 2 was 0.704 for the IORP, which shows trust, commitment, flexibility, coordination, communication, participation, and frequency of interaction substantial, explaining 70.4% of the variance in IORP. Table 5 presents the mediating role of trust and commitment (H5) from the specific indirect effects results analyzed to check the interaction influence between the exogenous variables and the mediating variables. The results in this study found that the mediating effect of TRUST on two constructs of AMP (COMU with β = 0.078, t = 3.147, p = 0.002; PART with β = 0.069, t = 2.411, p = 0.016), which concluded that the sign of the relationship between communication, participation, and commitment was found to be affected by TRUST, so TRUST was mediating the relationship between communication and commitment (H5-1a) at the 98% confidence level. Similarly, TRUST has mediated the relationship between participation and commitment (H5-1e) at the 98.4% confidence level, and thus these exogenous constructs had a positive indirect impact on commitment through trust, and hypothesis H5-1a and H5-1e were supported. However, the hypotheses H5-1b, H5-1c, and H5-1d were not significant, so they were rejected.
The results in this study found that the mediating effect of TRUST on two constructs of AMP (COMU with β = 0.055, t = 2.458, p = 0.014; PART with β = 0.048, t = 2.166, p = 0.030), which concluded that the sign of the relationship between communication, participation, and IORP were found to be affected by TRUST, so TRUST was found to mediate the relationship between communication and IORP (H5-3a) at the 98.6% confidence level. Similarly, TRUST has mediated the relationship between participation and IORP (H5-3e) at the 97% confidence level. Therefore, these exogenous constructs positively impacted inter-organizational relationship performance through trust, so the hypotheses H5-3a and H5-3e were supported. However, the hypotheses H5-3b, H5-3c, and H5-2d were not significant, so they were rejected. TRUST-COMIT had mediating effects. The results in this study found that the mediating effects of TRUST-COMIT on two constructs of AMP (COMU with β = 0.031, t = 2.880, p = 0.004; PART with β = 0.027, t = 2.331, p = 0.020), which concluded that the sign of the relationship between communication, participation, and inter-organizational relationship performance were found to be affected by TRUST-COMIT. Therefore, TRUST-COMIT has mediated the relationship between communication and IORP (H5-4a) at the 99.6% confidence level and IORP (H5-4e) at the 98% confidence level. Therefore, these exogenous constructs positively impacted IORP through TRUST-COMIT, and hypotheses H5-4a and H5-4e were supported. However, the hypotheses H5-4b, H5-4c, and H5-4d were not significant, so they were rejected. The findings indicated that the critical role of mediating trust-commitment between alliance management practices and inter-organizational relationship performance were statistically significant and had indirect effects. It was explained to be authentic and supported by a strong positive relationship from TRUST-COMIT and IORP.
Based on the results were tested H1 to H5 direct and indirect (see Tables 4 and 5), so the total effects of IORP are the sum of all direct and indirect effects of all constructs [66,77]. COMIT construct had the most considerable total effects on inter-organizational relationship performance, with path coefficient was 0.400, following CORD was 0.319, then TRUST was 0.281, FREQ was 0.235, and COMU was 0.226.

Discussions
This paper aims to identify what alliance management practices (AMP) factors affect inter-organizational relationship performance (IORP) by mediating trust and commitment between travel companies and their partners. To examine the relationships among these variables, we have proposed an IORP model that relies on prior theoretical research to select factors of AMP: trust, commitment, coordination, communication, flexibility, participation, and frequency of interaction influence the development of inter-organizational relationship performance. This current study has further proposed that trust-commitment would mediate factors of AMP in predicting IORP. The scale used for the constructs of trust, commitment, coordination, communication, participation, and frequency of interaction have shown appropriate results in our adaptation to the Vietnam tourism context. However, only the scale used for flexibility was not relevant to the results in our context.
First, our results proved that the mediating role of trust and commitment was a significant impact factor on inter-organizational relationship performance (see Figure 1). Our findings were supported by previous studies [9][10][11][12]. Moreover, our results provide additional support for this theory that contributed to inter-organizational relationship performance in Vietnam's tourism sectors. According to Palmatier et al. [10], in B2B relationships, there is an antecedent of commitment, trust had a positive effect on IORP, and the key mediating variables were based on "the increase total sales, sales growth, cooperation, trust in a high degree of harmony, always do the right things, benefit expectations and capability to implement the objectives, had high integrity." In the marketing field, Morgan and Hunt [12] had an empirical study between retailers and suppliers, and their findings found that trust had a positive effect on commitment, relationship success, and trust-commitment were key mediating variables in the relationship between retailers and suppliers also essential variables in marketing relationships. Furthermore, Ashnai et al. [12] had an empirical test of B2B relationships with 334 surveys. They found that trust positively affected commitment and relationship outcomes. Thus, commitment played a crucial role in identifying the relationship in B2B. Second, to answer the question of what the travel companies and their partners should do to overcome the crisis caused by the COVID-19 pandemic, we identify what factors of alliance management practices affect inter-organizational relationship performance. Four of the seven exogenous variables (COMIT, CORD, TRUST, FREQ) have a significant and direct effect on IORP. The path analysis showed that commitment had the most extensive positive significant impact on inter-organizational relationship performance, confirmed by previous studies [7][8][9][10][11][12]. Following this is coordination, which was found to be the second-most robust value directly affecting inter-organizational relationship performance. These findings had already been confirmed by [7][8][9], and their results showed coordination had a positive significant direct impact on IORP. This study found that the role of inter-organizational trust is a central and key variable in the relationships between travel companies and their partners in inter-organizational relationship performance. Trust has direct and indirect impact IORP, and our findings were consistent with the transaction cost theory: "all things in the relationship must be clear and equal, based on trust can manage the better stress and show the greater flexibility and adaptability in uncertainty environment" [70]. Similar to the findings of Ashnai et al., [11] found that the greater inter-organizational trust would result in improved alliance performance: "relationship satisfaction, trust in stable business partnerships, which seek for developing the relationship by discussing and specifying the tasks, responsibilities, plans, investments, accountability, time frames of each party." In addition, this finding consisted of previous scholars showing that inter-organizational trust was built upon the benefits expectations and capability to implement the objectives from partners [11,27,28]. Finally, this study found the frequency of interaction was the fourth most substantial value significant direct effect on IORP, which seems to be in line with the findings by [30,53], who confirmed a positive correlation between frequency of interaction and IORP. As Christopher [53] found that "the frequent interactions among organizations might contribute to the development of long-standing and valuable relations, increase the level of cooperation" [44,54]. According to Turker [30], "the organizations should maintain contact with other organizations to survive in a competitive environment." This present study cannot predict the antecedent of flexibility, and flexibility did not significantly affect trust, commitment, and IORP. This outcome of flexibility was contrary to that of [22], who showed that the flexibility factor was positively associated with the IORP (Beta = 0.17, p < 0.05, respectively), performance was influenced by flexibility (Beta = 0.605, p < 0.01) [51], and flexibility enhances performance in bilateral alliances [45].
Finally, in this study, we found that communication and participation indirectly affect IORP through both mediating trust and commitment. These results match those observed in earlier studies [9][10][11][12]. Similarly, Cote and Latham [13] also confirmed that the inter-organizational trust and commitment towards the relationship were the mediating variables that lead to IORP and would reduce the uncertainty results from opportunism and minimize the expectation for controlling the broad procedures [12,14]. This finding defined trust and commitment as the mediating variables and showed that these factors were associated with IORP [9][10][11][12].
In summary, to compare our findings and previous research, in our study, the subjects were travel companies founded alliances with accommodation, restaurants, transportation companies, tourist attractions, shopping centers, and previous research the population target was B2B relationships or dyadic relationships (sellers and customers, retailers and suppliers, hotels and agencies). The findings suggest three different strategies to build inter-organizational relationship performance in this study. The first emphasizes building inter-organizational communication, coordination, and participation among alliances, which will lead to inter-organizational commitment to increase total sales, share resources, sales growth, cooperation, benefit expectations, and the capability to implement the mutual objectives. Connecting with sharing these activities between travel companies and their business partners will strengthen inter-organizational relationship performance development. The second implication is strengthening inter-organizational relationship performance, emphasizing strategies based on inter-organizational communication and participation among travel companies and their business partners. It is important to enhance inter-organizational trust to increase a high degree of harmony, trust our partner's decisions, competence, and abilities to fulfill agreements and promises to share resources and operational strategies. Implementing these activities between travel companies and their business partners will build more robust inter-organizational relationship performances. Additionally, inter-organizational trust and commitment are the simultaneous processes that increase a high level of trust and commitment to control resources scarcity and operational strategies, which can both build a thriving cooperative strategy rely on inter-organizational relationship performance. Finally, the pandemic has wholly crippled the Vietnamese tourism industry, so we needed to conduct this research to find what factors lead to alliance success (see the results in Tables 4 and 5). We then use these factors to give solutions and strategies to recover and prepare for the post-pandemic tourism industry. So, all tourism sectors must stand together to achieve mutual goals to overcome the pandemic.

Conclusions and Limitations
This study draws some implications and suggestions for managers of tourism sectors, policymakers, and government. In previous years before COVID-19 pandemic breaks out, the booming tourism industry in Vietnam depends on inter-organizational relationship performance. The higher IORP increase the ability to succeed. However, travel companies and their business partners should develop alliance strategies and build sustainable tourism based on enhancing trust, commitment, coordination, and frequent interaction directly affecting IORP. In addition, focusing on building the participation and communication that builds trust and commitment indirectly increases the strength of IORP development.
In particular, to overcome, recover, and prepare for the post-pandemic tourism industry, the travel companies and their partners develop alliance strategies and build sustainable tourism. First, they should fulfill their commitment together to protect the society and the environment they are exploiting. Tourism organizations should form strategic relationships to strengthen commitments: reduce prices together, use local products, support other partners to implement sustainable goals, plan ecotourism services with conservation; thereby, tourism sectors can reduce costs or minimize transaction costs when they interact together and increase the operative efficiency [16].
Second, all parties should coordinate more by delivering knowledge about sustainable development to all staff and partners, so they need to open courses to educate and train them on implementing sustainability and protecting the environment. In addition, the travel companies and tourism sectors should commit to implementing pay reasonable award salaries for staff and not using child labor or forced labor. In addition, the government and policymakers should have a financial package to support tourism sectors as well as the workforce in the tourism industry, such as reducing corporate taxes and personal income tax, supporting salary for the workforce, and providing loans with low-interest rates for a long time to recover the tourism industry.
Third, the travel companies and their partners should improve local economic development by using the local services in destinations. They should consider frequent interaction and involvement with their partners and the local citizens to campaign for protecting the environment in destinations by donating money and facilities for the local people to protect the environment and conserve wildlife. In addition, the travel companies and tourism managers should propagandize that all staff and guests commit to saving energy and water, commit to balancing biodiversity, avoid increased pollution and waste by building environmental management systems in destinations, and use green products. The travel companies and their partners should restore travel confidence by working together to implement commitment priority "safe and clean" by protecting health and safety provisions for guests such as the restaurants and bars implementing a commitment to serving healthy food and not serve wild animal dishes. The rumor said that "the SARS-CoV-2 pandemic was appeared because of eating wild animal dishes". So, the tourism sectors also have a significant opportunity to drive change. It drives all tourism sectors to quickly form exchange partnerships to work together and promote service systems by working at home, sending all information and documents by email, conducting meetings with partners carried out via Zoom, a virtual meeting software that improved staff efficiency, and making decisions quickly in the tourism sector.
This study has some limitations. First, the limitation of this study is the data were collected during the COVID-19 pandemic, so it was not easy to approach target samples to carry out the surveys, so we did not reach an objective about sample size. Second, the proposed factors and perspectives were adapted from previous studies that may be weak in our context, or the statements might not appear clearly. Third, this study used only the quantitative method to evaluate the examined aspects, so future research should use qualitative and quantitative methods and apply this model in the economic field, the social field, the health care and beauty salon field, and the environmental context. Finally, this study focused only on travel companies and travel agencies, so the study did not get many perspectives from all parties. Therefore, future studies should survey all tourism sectors in Vietnam to address general issues.