Perceived Organizational Performance in Recruiting and Retaining Employees with Respect to Different Generational Groups of Employees and Sustainable Human Resource Management

Organizational performance is considered as the essence of an industrial enterprises’ existence. However, in terms of performance, it is important not only to achieve results, but also maintain and develop the potential of an enterprise. When assessing performance, industrial management often omits the organizational success in managing human resources and developing human resources potential. The main aim of this paper is to present the research results focused on perceived organizational performance in recruiting and retaining employees with respect to different generations of employees in industrial enterprises. For the purposes of the analysis, the authors of the paper have designed a valid and reliable collection tool (research questionnaire). The research sample consisted of N = 1471 respondents, employees of industrial enterprises in the Slovak Republic. The research result shows that different generations of employees perceive differently selected issues of organizational performance. Testing the first research hypothesis has proved that there is a significant difference between employees from different generational groups in the perception of relationships among employees. The testing of the second research hypothesis confirmed that there is a statistically significant relationship between selected issues of perceived organizational performance.


Introduction
A meaningful utilization of the enterprises' human resources is a precondition for taking advantage of the human resources potential. In order to enable the employees in an organization to perform at the required performance level, it is indispensable for them not only to have created the necessary conditions [1][2][3] but also to have the required competencies [4][5][6]. However, it is also important that they are sufficiently motivated [7,8] or engaged [9] to perform. These factors affecting work performance can be influenced by targeted activities and practices of human resource management. The basic precondition is that the organization dispose the human resources with necessary potential [10]. In this respect, the recruiting and retaining the staff plays an important role in ensuring the conditions for employees' performance.
The aim of the paper is to present the research focused on examination of perceived organizational performance and human resource management procedures, aimed at recruiting and retaining the employees with respect to different employees' generations in industrial enterprises. In order to  Figure 1 shows that the functional model is in line with sustainable human resource management which aims to manage human resources in a sustainable way [34]. Given the importance of human resource management practices for the business performance of enterprises, efforts should be made to adequately adapt and implement human resource management practices in order to improve the performance of enterprises.
Demographic evolution as well as many studies in this field [28,35,36] point out that organizations must cope with an aging workforce. In addition, several generations of employees meet at the workplace. Each of them manifests typical attitudes to work, values, and motivational preferences [37,38]. That is why it is important to consider the structure and diversity of the workforce in the organization when managing the organization's human resources, and especially in areas such as performance management. The term 'generation' can be understood as a group of people or a cohort which have common years of birth and also some experience as they live in the same time period [39].
The generation of Veterans, named also as Silent Generation, Seniors, Matures, or Builders, consists from people born in . Some social, cultural, political, and economic affairs are the main events that members of this generation abided in their lives and formed their personal characteristics. Wars and economy hardships are the main events traditionalists suffered as they lived a substantial part of their lives under their consequences. Most of their features are influenced by these sufferings. That is why conservative traditionalists, who want to protect and lead a modest life  Figure 1 shows that the functional model is in line with sustainable human resource management which aims to manage human resources in a sustainable way [34]. Given the importance of human resource management practices for the business performance of enterprises, efforts should be made to adequately adapt and implement human resource management practices in order to improve the performance of enterprises.
Demographic evolution as well as many studies in this field [28,35,36] point out that organizations must cope with an aging workforce. In addition, several generations of employees meet at the workplace. Each of them manifests typical attitudes to work, values, and motivational preferences [37,38]. That is why it is important to consider the structure and diversity of the workforce in the organization when managing the organization's human resources, and especially in areas such as performance management. The term 'generation' can be understood as a group of people or a cohort which have common years of birth and also some experience as they live in the same time period [39].
The generation of Veterans, named also as Silent Generation, Seniors, Matures, or Builders, consists from people born in . Some social, cultural, political, and economic affairs are the main events that members of this generation abided in their lives and formed their personal characteristics. Wars and economy hardships are the main events traditionalists suffered as they lived a substantial part of their lives under their consequences. Most of their features are influenced by these sufferings. That is why conservative traditionalists, who want to protect and lead a modest life without spending much, and they need stability. Permanent work and financial security are essential for these people. They prefer security and authority [40]. Members of this generation are currently in the labor market only in exceptional and specific professions, but their approach to work has influenced future generations of employees [41].
The post-war generation of people is a generation also known as Baby Boomers, born in 1946-1960. This generation was required to perform tasks at work and the ambition or initiative was perceived as an obstacle. The rush to work was not caused by enthusiasm but by the necessity to arrive on time, while workers were supervised to ensure that they did not damage or steal property. Work was an essential part of life and not a way of job satisfaction [42]. Baby boomers expect that the experience and expertise they bring to the workplace and to the work teams will be respected [43]. Sometimes they are considered individualistic and selfish, unwilling to retire [44].
Employees belonging to Generation X, born in 1961-1980, expect career development from work, although it is not necessarily straightforward, and growth. They want to have a life beyond work, expecting recognition of individualized pay and flexible working time [43,45,46]. They care for themselves and do not want to be dependent on anyone [47]. They are more committed to people than organizations [48]. They formed a circle of friends with whom they were in contact when they parents were at work. Although they consider themselves individualists, they are very dependent on the support and assessment of their friends [49]. However, the high demands of others may endanger long-term relationships and increase the need for autonomy [50]. Many of the Generation X members are afraid of being dismissed and fear that they will lose their jobs [41].
Generation Y, born in 1981-1995, is considered as a mobile generation. It is therefore an advantage for them if they can return after they leave the employer [51]. Lack of incentives makes them reluctant to retain and stay with the employer [52]. Employees from this generation expect stability from the employer and are characterized by high expectations. If they are not fulfilled, they only do what they are paid for and do not intend to remain with the employer, seeking new employment opportunities to find new and better jobs [53]. Generation Y members are very social and appreciate friendship and personal relations. They like to work in teams and with their friends. They are noisy at work and enjoy working in a friendly atmosphere, so their teamwork seems like social event [37][38][39][40][41][42][43][44][45][46][47][48][49][50][51][52][53][54].
The members of generation born in 1996-2009 are referred to as the Generation Z. The Generation Z is increasingly concerned about the environment. Increasing interest in the environment is caused by increasing environmental awareness, which, however, varies according to their level of interest in environmental issues and sustainability behaviors [55]. The influence or pressure of peers affects their behavior [56]. The members of the Generation Z prove to be more independent of their colleagues and thus much more dependent on their own abilities and competencies. They may but must not to share their same generational belonging with their co-workers [57]. In addition to the opportunity for self-realization and meaningful work they expect to have team of friendly colleagues [58].
It may be challenging for employers to find ways how to attract, manage and retain young talent. The key is to know their individual preferences and needs to know how to meet their expectations [59]. The young generation is becoming a challenge for employers because as they tend to change employers. This negative trend in Slovakia is reinforced by the migration of the young generation abroad [60]. The employers will have to consider the interests and needs of Generation Z beyond financial compensation such as open communication, fair action, and flexibility in employment or social responsibility. Employees of this generational group also appreciate mentoring [61]. They like a feeling of freedom when possible, but they also appreciate the willingness to provide guidance [62]. Generations Y and Z are sometimes collectively referred to as Millennials. The millennials are recognized as enjoyable collaborators and shared values are more important to them for the perception of meaningful work than to older generations [63].
The inclusion of an individual in a very cohesive work group affects employee satisfaction with different work aspects [64,65]. This has implications for working behavior. A demographic age study showed, if employees differ in age from the working group, that it lowers the level of integration in the workgroup and increases employees' retirements [66]. Therefore, it is important to investigate perceived relationships in the workplace, also regarding the age diversity.

Research Hypothesis 1:
There is a statistically significant difference between various generational groups of employees in the perceived relationships among employees.
Managers and leaders of organizations and enterprises do not have to cope only with aging employees and new attitudes and approaches to work. What they also must face is recruitment, efficient utilization, and retention of the workforce. The ability to cope with these challenges through efficient human resource management in all areas of sustainable development has significant implications for the existence of enterprise in the future. Moreover, demonstrating the responsibility of organizations in the sustainability field should have a side positive effect. Even a slight reduction in employee fluctuation and turnover can pay off in general, especially for key employees. It is important for enterprises to see how employees are involved and integrated into the work teams and collectives [67].
There may seem to be little real evidence that human resources policies and practices are improving the performance of the organization. However, the evidence continues to grow and, although it takes a long time for long-term data to exist, the evidence is consistent with the view that human resources policies and practices within the organization have a strong impact on employee motivation to manifest the different attitudes and behaviors needed to support and implement organization strategies [68]. All employees themselves are sometimes overlooked as a source of sustainable competitive advantage as their benefits to the enterprises are less visible. Nevertheless, these employees can play an important role in creating a competitive advantage as they directly influence the production of a product or service. Teams or collectives of employees manifest various social complexity (good co-working relations, trust, etc.) that could not be imitable, but beneficial for involved employees. Consequently, it can be concluded that usually they are top managers or specialists, who are clearly valuable. These employees and can provide visible competitive advantage, but usually a short-term a sustainable competitive advantage should be more probably to be found across the whole human resources and their potential [69].
Not only formal but also informal relationships are important for the effectiveness of the working collectives. Informal relationships are an extrapolation of formal relationships. However, informal relationships support formal relationships. Moreover, it was confirmed, that relations between employees greatly affect the coherence of working teams [70]. Interaction with other people can be a source of conflict, stress, but also support. Bad relationships include low confidence, low support, and low interest in listening or dealing with problems [71]. Working groups' coherence, conflict rates and their impact on work performance and achievement are also influenced by cultural aspects [72,73]. However, scientific studies have pointed to the impact of conflicts in the workplace as well as in the life beyond work [74,75]. The degree to which individual employees perceive that they are expected to manifest the desired positive emotions and suppress negative emotions at work is a catalyzer for burnout. The degree of conflict at work also affects conflicts between work and family life [75]. Social support from a supervisor or colleagues allows reducing the impact of workplace stress that affects performance degradation [76]. Socializing newly recruited employees allows them to be integrated into the collective and reduces fluctuation and employees´turnover. The inclusion of new employees in the team increases integration in employment and active involvement of employees [77]. Sustainable human resource management is seen as a way to, among other things, ensure enterprises to attract and retain talented employees, maintain employees, invest in the skills of employees on a long-term basis, manage aging workforces, and create sustained employee relationships [78].
For newly hired employees and their retention in work, it is important to learn how to do work (recognized as conscientiousness) [38], but also to meet the 'right' people from whom they can learn about the organization processes and so enable their job embeddedness. This will ensure not only lower turnover in the early stages of employee adaptation and performance assurance. It is confirmed that people decided to stay in the enterprise are more efficient and provide higher performance [79]. Colleagues and superiors contribute to creating a social working environment. A pleasant and healthy work environment has a positive impact on direct impact on work efficiency and employeesṕ erformance [80][81][82]. Increasing satisfaction with co-workers also increases pro-social behavior towards co-workers, which benefit not only for co-workers, but also for the organizations themselves [83]. Relationships between employees with each other and supervisors and employees affect performance in a different way through the perception of both, information and interpersonal justice. The quality of relationships between employees and co-workers further enhances work performance by motivating employees to engage in learning and sharing knowledge [84]. Employees are more personally interested in the welfare of the organizations in which they work and are more motivated to contribute to collective success if they have more positive relationship to their co-workers [85]. Supportive behavior by supervisors and assistance from co-workers mutually interact and enable individuals to face high work pressure. The interaction of this support is crucial to avert the threat of loss of employees in the organization [86]. Based on this, we hypothesized that relationships with co-workers and lowest turnover of employees are in positive relation.

Research Hypothesis 2:
There is a statistically significant relation between the perceived relationships among employees and perceived organizational ability to retain important employees. Figure 2 shows the logic of the formulated research hypothesis 2. The social working environment of an organization is created by formal, informal as well as symmetric and asymmetric relationships. Asymmetrical relationships result from vertical organizational management structures within an organization (they represent management relationships with other employees), which may not be only the relationship between the direct supervisor and the employee. Symmetric relationships can be understood as relationships between employees at the same level of organizational hierarchy. Demonstrating the existence of a statistically significant relation between relationships among employees and the ability to retain important employees can provide the information needed in a human resource management system with an emphasis on the stabilization of organization's employees.
Sustainability 2020, 12, x FOR PEER REVIEW 6 of 24 that people decided to stay in the enterprise are more efficient and provide higher performance [79]. Colleagues and superiors contribute to creating a social working environment. A pleasant and healthy work environment has a positive impact on direct impact on work efficiency and employees´ performance [80][81][82]. Increasing satisfaction with co-workers also increases pro-social behavior towards co-workers, which benefit not only for co-workers, but also for the organizations themselves [83]. Relationships between employees with each other and supervisors and employees affect performance in a different way through the perception of both, information and interpersonal justice. The quality of relationships between employees and co-workers further enhances work performance by motivating employees to engage in learning and sharing knowledge [84]. Employees are more personally interested in the welfare of the organizations in which they work and are more motivated to contribute to collective success if they have more positive relationship to their co-workers [85]. Supportive behavior by supervisors and assistance from co-workers mutually interact and enable individuals to face high work pressure. The interaction of this support is crucial to avert the threat of loss of employees in the organization [86]. Based on this, we hypothesized that relationships with coworkers and lowest turnover of employees are in positive relation.

Research Hypothesis 2:
There is a statistically significant relation between the perceived relationships among employees and perceived organizational ability to retain important employees. Figure 2 shows the logic of the formulated research hypothesis 2. The social working environment of an organization is created by formal, informal as well as symmetric and asymmetric relationships. Asymmetrical relationships result from vertical organizational management structures within an organization (they represent management relationships with other employees), which may not be only the relationship between the direct supervisor and the employee. Symmetric relationships can be understood as relationships between employees at the same level of organizational hierarchy. Demonstrating the existence of a statistically significant relation between relationships among employees and the ability to retain important employees can provide the information needed in a human resource management system with an emphasis on the stabilization of organization's employees. Organizational ability to attract and retain important employees is precondition for creation the sustainable social potential of the enterprise ( Figure 2). Such potential enables the management of enterprises to support desirable behaviors and to form positive relationships in organization through targeted activities in sustainable human resource management. Organizational ability to attract and retain important employees is precondition for creation the sustainable social potential of the enterprise ( Figure 2). Such potential enables the management of enterprises to support desirable behaviors and to form positive relationships in organization through targeted activities in sustainable human resource management.

Materials and Methods
The main aim of the research was to examine the perceived organizational performance and human resource management practices that are focused on the recruiting and retention of staff and their perception with respect to different generations of employees.
In order to fulfill the main aim of the research we have determined two research questions and formulated two research hypotheses. Initially, research questions were set out to frame and address the research problem. Afterwards, we defined research hypotheses to answer our research questions. The research hypotheses are formulated in the previous part of the paper following the theoretical background. The research questions and hypotheses were defined based on analysis and synthesis of theoretical knowledge, scientific studies and experiments, and based on the authors' practical experience in human resource management area.

Materials and Methods
The main aim of the research was to examine the perceived organizational performance and human resource management practices that are focused on the recruiting and retention of staff and their perception with respect to different generations of employees.
In order to fulfill the main aim of the research we have determined two research questions and formulated two research hypotheses. Initially, research questions were set out to frame and address the research problem. Afterwards, we defined research hypotheses to answer our research questions. The research hypotheses are formulated in the previous part of the paper following the theoretical background. The research questions and hypotheses were defined based on analysis and synthesis of theoretical knowledge, scientific studies and experiments, and based on the authors' practical experience in human resource management area.

Research Question 2: How do employees from different generational groups perceive relationships between managers and other employees and relationships among employees in general in their organization?
The research sample consisted of employees of industrial enterprises operating in the Slovak Republic. For better representativeness of the sample, we decided to include into the research sample employees employed in industrial enterprises of all sizes and members of all generational employees' groups present in the labor market. Respondents were addressed personally by authors and voluntary data collectors, and questionnaires were distributed exclusively in paper form. Subsequently, the collected data were processed in Microsoft Excel. Overall, N = 1471 respondents (employees of industrial enterprises) participated in the research. The distribution of the respondents by date of birth in absolute frequency of answers is shown in the Figure 3.  Table 1.   Table 1. In Table 1 it is shown the generational structure of respondents by classification to their appropriate generational group. The data in the table shows that the respondents belonging to the Generation X (39.84%) and Y (52.35%) have the largest representation. The above results also reflect the current representation of the working population in the Slovak Republic in recent years. Some respondents did not answer the question concerning the date of birth, but these respondents answered other items of the questionnaire, and therefore were included in the group without answers (13). The following Table 2 shows all respondents distribution by job classification. The Table 2 shows that administrative employees have the largest representation from all analyzed respondents (42.90%), the next largest group are production employees, who accounted for 549 of 1471 respondents (37.32%). The respondents working in managing positions have the lowest representation (18.49%). Some respondents did not answer the question concerning the job classification, but these respondents answered other items of the questionnaire, and therefore were included in the group without answers (19).
For the purpose of data collection was constructed valid collection tool (the research questionnaire). Socio-demographic questions and questions relating to perceived organizational performance were used to construct the research questionnaire. Socio-demographic questions related the territorial scope of organization, the number of employees in the organization, gender, job classification, and date of birth of the respondents. For questions regarding the perceived organizational performance, respondents could choose as an option following answers: much worse, worse, better, much better. The reliability of the data collection tool in terms of the internal consistency of the questionnaire was carried out by calculating the Cronbach's coefficient alpha. For items relating to the perceived organizational performance, the Cronbach's coefficient alpha reached a level of 0.85 therefore we can say that the data collection tool is sufficient for scientific purpose [87].
The distribution of the data collection tool (the research questionnaire) and the creation of the research sample were selected through multi-stage random conglomerate sampling. The questionnaire was distributed directly to employees of industrial enterprises in paper form to ensure interaction with the respondents and familiarization with the way of completing individual items of the research questionnaire. Data collection was carried out from September 2018 to January 2019. During the processing of the results, the anonymity of individual respondents was preserved.
To evaluate the collected data, the authors of the paper used the methods of descriptive statistical analysis, the results were interpreted in the form of tables (cross-tables, tables of absolute and relative frequencies and supplementary tables of statistical test results) and in the form of graphical representation (polygon). The data collected were processed in Microsoft Excel. Furthermore, non-parametric statistical tests were used to identify the statistically significant differences and relationships between the selected dependent and independent variables. Namely there were used the following tests: Pearson's chi-squared test or Chi-squared test and Spearman's rho correlation coefficient. The abovementioned statistical tests were conducted to evaluate the determined research hypotheses in the IBM SPSS 22.0 (Statistical Package for the Social Sciences). The significance level was significant at a 0.01 (significance level α = 1%) level. It follows that the obtained and interpreted results can be considered statistically significant. The basic thought processes such as comparison, analysis, synthesis, abstraction, generalization and deduction were used in all parts of the paper (from introduction to discussion).

Research Results
The following part of the paper is divided into two partial sections. The first one is focused on evaluation and interpretation of the determined research questions. The second one contains the results of testing research hypotheses defined.

Results for Research Questions
As mentioned above, different variables can be identified to analyze perceived organizational performance in area of sustainable human resource management. The authors of the paper have focused on the field of organizational performance which is closely related to organizational culture and interpersonal relationships.

Research question 1: How do employees in different job positions perceive the ability of their organization to attract and retain important employees?
Within the research area framed by the first research question, there were two chosen variables, which are primary preconditions for human potential development, internal motivation and consecutive the job performance of employees. The first variable is the ability to attract important new employees, which is perceived differently by various generations of employees. The results can be seen in Table 3. Table 3 shows that the most critical (much worse) perceived organizational ability to attract new employees is the production employees (14.75%), followed by administrative employees (10.30%). The ability to attract new employees to the organization also production employees (42.81%) perceive as worse, followed by administrative employees (38.51%). On the other hand, respondents at managerial positions perceive organizational ability as much better (14.34%), followed by administration (13.15%). The ability to attract important newcomers was indicated as better by respondents at managerial positions (41.18%), followed by administration (37.08%). The research results proved that employees at various work positions perceive this organizational performance variable differently (values are highlighted in Table 3).
The second part of the first research question deals with perceived organizational performance variable, namely the ability to retain important employees. We decided to examine the view differentiated with respect to different positions of employees (production, administrative, and managerial staff). This item is closely linked to the performance given due to the motivation and the hierarchy of needs. If the employee does not feel recognized and is not informed how valued his/her contribution is, his/her internal motivation decreases, and the work performance is reduced. The results for perceived organizational ability to retain important employees can be seen in Table 4. The Table 4 shows that employees at different positions differently perceive the variable ability to retain important employees. Administrative employees consider the worst ability to retain employees in the organization in which they work. Production employees perceive the ability to retain important employees worse. It has been unequivocally shown to the management that when comparing the perceived ability to retain important employees among different jobs, it is the management that they consider to be better and much better. This was influenced by the fact that it is the management that makes decisions about the importance of various positions within the organization. If we do not compare the results by the job positions, it can be declared that a total of 663 respondents (45.08%) perceive that industrial enterprises they work for are worse in their ability to retain important employees, compared to similar organizations. On the other hand, up to 793 respondents (53.91%) perceive that industrial enterprises they work for can retain important employees.

Research Question 2: How do employees from different generational groups perceive relationships between managers and other employees and relationships among employees in general in their organization?
The second research question was focused on perceived relationships within organization. The first analyzed variable of perceived organizational performance was the relationships between managers and other employees. The abovementioned variable has a great influence on the performance of employees. Inner well-being or employee discomfort often depends on relationships at the workplace within vertical structures. If the employees are treated well and manager use appropriate leadership style, he/she can create an ambient working atmosphere and the performance of employees is higher than otherwise. The results of the examination of the relationships between managers and other employees are differentiated by various generational groups of employees can be seen in Table 5.
It can be seen from Table 5 that the results are differentiated according to the respondents' belonging to individual generational groups (highlighted values). In the generation of Baby Boomers, the largest group of respondents think that relationships between managers and employees are within their organization they work for better, but at the same time the second most common answer is that they are worse compared to other organizations. The answers are similar in Generation X, and it is Generation X that most often indicated that relationships are worse compared to other generational groups. The members of Generation Y, most frequently respond that relationships are better and then worse similarly than in the previous two groups. However, no option is the most numerous in comparison with other generations of employees. The distribution of answers among Generation Z members is similar as in other generational groups. Therefore, the most frequently response answer within the generational group is the better and then the option worse. When comparing all generations, it is the Generation Z that regards workplace relationships much better and much worse than other generations. It follows from analyzed results that perception of relationships between managers and other employees among various generations is very similar but in comparative analysis between all generations we find that the analyzed variable is perceived differently between different generations. This implies that age is the factor that influences different perceptions of variables of perceived organizational performance.
The last variable to be examined in perceived organizational performance is the relationship between employees in general. We suppose that this factor is determining for employee work behavior and strongly influences the decision-making about keeping or leaving the job. We also suppose that workplace relations affect the performance of employees due to that positive workplace relationships facilitate mutual help and support from colleagues and negative relationships caused absenteeism and fluctuation in effort to avoid unpleasant working surrounding. The research results analysis for this variable can be seen in Table 6 below.  Based on the comparative analysis of data found in Table 6, it can be assumed that the perception of workplace relations between employees is generally different from the point of view of the various generations of employees in industrial enterprises. If the relations with other employees were perceived much worse, the largest part of respondents was from generation Baby Boomers. Generation X perceives the workplace relationships as worse. On the other hand, Generation Y respondents consider workplace relationships as better compared to other organizations. Employees from Generation Z identified relationships at the workplace as much better.

Results for Research Hypotheses
Age diversity influences perceived organizational performance issues, as confirmed the results for research questions. Thus, we could approach to testing the research hypotheses.

Research Hypothesis 1:
There is a statistically significant difference between various generational groups of employees in the perceived relationships among employees.
After testing the hypothesis 1, the difference between different generations of employees and relationship between employees in general was confirmed. The results of these variables can be seen in Table 7 shown below.  Table 7 it is apparent that the perceived relationships in the workplace are perceived differently by various generational groups of employees. It follows that we can assume a statistical difference between the monitored variables. To evaluate the hypothesis of the research was carried out statistical test Pearson chi-Square, the outcome of which can be seen in the Table 8. Based on the research results, it can be argued that there is a statistically significant difference (p < 0.001) between all four generations of employees in the perception of employees' relationships with each other, as shown in Table 8 above. In order to specify the difference, a correlation analysis was also carried out, the results can be seen in Table 9 below. Table 9. Correlations: Spearman's rho for relationships to other employees across generational groups (Source: own elaboration, 2019).
As can be seen in Table 9, there is a statistically significant relationship between selected generations and perceived relationships between employees in general. A weak correlation which is statistically significant (Spearman's rho = 0.118; p < 0.001) can be observed. This significant relationship can be expressed in the following way: the younger the employee, the better his/her perception of the evaluated item. Based on the analyzed data in Tables 8 and 9, it can be concluded that the first research hypothesis can be confirmed, and it can be argued that there is a statistically significant difference in the perception of this item between different generations of employees.

Research Hypothesis 2:
There is a statistically significant relation between the perceived relationships among employees and perceived organizational ability to retain important employees.
The second research hypothesis supposes the statistical relationship between the perceived variables of organizational performance declared by positive relationships between employees in general and the ability to retain important employees. A pairwise comparison of selected variables can be seen in Table 10, in a cross-table interpretation form.   Table 10. Perceived relationships between employees and perceived ability to retain important employees (Source: own elaboration, 2019). In Table 10 the results adjusted for respondents who did not answer questions about the ability to retain important employees and employee relationships in general are shown. As a result, it is clear that the perception of the item relationships between employees in general are correlated with the variable perceived ability to retain important employees. To test the hypothesis, a Spearman's rho correlation test was proceeded, the result can be seen in Table 11. Table 11. Correlations: Spearman's rho for perceived relationships between employees and perceived ability to retain important employees (Source: own elaboration, 2019).
As can be seen in Table 11, there is a moderate positive and statistically significant relationship between organizational performance variable perceived ability to retain important employees and organizational performance variable perceived relationships among employees (Spearman's rho = 0.355; p < 0.001). Based on the above, we do not reject the second research hypothesis, and we can conclude that good relationships at the workplace with other employees positively affect the ability to retain important employees in industrial enterprises.

Discussion
Many organizations have to deal with an increasingly diversified workforce. It is not only aging that has made labor management more difficult because it is more diversified [88], but also the fact that employees are highly qualified and aware of their rights to work in an organization [89]. Global demographers have long predicted a parallel demographic shift from a balanced workforce of older and younger workers to an unbalanced workforce dominated by older workers [90] and emphasize the importance of sustainable human resource management, as well as maintaining or improvement the sustainable employability of their workforce [28]. It can be assumed that developing programs to encourage older workers to actively contribute to results and create added value in their organizations is a challenge that organizations should consider as an investment [91].
Therefore, in our opinion, it is important to consider the age diversity of the workforce when managing human resources in an organization. This will make it possible to take account of differences in attitudes of values and preferences and to exploit the coexistence of employees of different generations to achieve synergy of joint results. For this reason, it is possible to use the findings of the carried-out research and implement them into business practice. Investigated research suggests that there are significant differences between similar generations [35,43,48,92]. These differences seem more to be highlighted in the business environment when a number of issues arise in collaborative workplaces-notably in the area of knowledge sharing and knowledge transfer regarding the characteristics of the generations being compared.
The need to explore the motivation and willingness to share knowledge is emphasized by several authors [93,94]. Although human resources practices do not have direct impact on knowledge sharing, they have a positive indirect effect when they mediate relationship between commitment to organization and knowledge sharing [95]. This means that human resource management practices contribute to knowledge creation and create the emotional commitment needed for willingness of employees to share their knowledge [96]. Knowledge transfer is especially important for overcoming difficulties and increasing cooperation between generations, especially when younger and older employees work together in an organization [92].
We focused on the perception of relationships among employees and on how the perception of these relationships varies with different generations of employees, in the presented paper. Research has confirmed that employee relationships are perceived differently by different generations of employees. Research has shown that the younger the employees, the more they tend to positively evaluate the relationships between employees with each other. The study of unethical workplace behavior and the age categories of employees at risk of chicane has also demonstrated that age diversity plays role in workplace behavior towards colleagues [97]. We assume that differences in behavior towards colleagues are influenced by the age and generational diversity of employees. The perception of relationships between colleagues is incurred by values and accessibility, or openness to building relationships and the degree of experience, which varies from generation to generation of employees. The need to investigate the issue of relations between employees in terms of age diversity is also confirmed by another research. Millennium Generation employees are not just part of another generation, because they also share some of the value aspects and orientations of the previous generation. As a practical consequence, the behavioral and organizational characteristics that combine X and Y generation preferences should be identified in order to improve relationships between employees. The social implications of studying generational characteristics and tendencies in the workplace are an important social area, as it brings a new perspective on workplace relationships and leadership [98].
Although some authors have not confirmed that the relationship with co-workers has a significant impact on job satisfaction, they confirm that an appropriate working environment enhances employee loyalty, commitment and hence productivity [89]. However, other studies have confirmed that relationships have a significant impact on employee job satisfaction [99,100]. The presented research also confirmed that relations in the workplace have a significant impact on the work behavior of employees and the willingness to remain at work with the current employer in the organizations operating in Slovakia. The relationship between perceived relationships and perception of organizational performance in issues connected with recruiting and retaining staff has been confirmed by the results of the presented research. Research results have shown that the perception of workplace relationships as positive and the ability to retain important employees are positively interrelated. This finding needs to be incorporated in the sustainable human resource management.
Several studies deal with workplace conflicts and their impact on workplace relationships, wellbeing and employee performance [101][102][103]. The authors attribute an important role to managers' approach to conflicts in workplace [104,105]. The conflicts are seen as a symptom of management failure that should be avoided because it distracts attention from the primary goal of creating high-performance organizations [106]. The direct effects of culture on the direction and supportive leadership and team cohesion as well as on the mitigating impact of social culture on the relationship between leadership and working group cohesion are not negligible [107]. The organization's commitment to corporate social responsibility, especially in the social area and the approach of managers, play an important role in the perceived burden on performance and affect how employees feel safe at work [3,108].
We have also assumed that the ability of an organization to retain important employees will be differently perceived by employees at different working positions. The managers perceived more positively the ability to retain important employees as production and administrative employees as confirmed results of presented research. An interesting area for exploring would be the perception of difference s between managers and other employees and the ability to retain important employees in terms of gender diversity. Some research on the assumptions for managerial work declares differences in the approach to managerial work between men and women [109], but also in the conditions created for their work [110]. The presented results of carried out research and previous meta-analysis have shown that the proposed functional model together with the research results after their application can have a positive impact on sustainable human resource management and afterward on organizational performance of the enterprises.

Conclusions
The presented study also has several limitations and future proposals. The authors aimed on sustainable human resource management with focus on the potential of employees. The relationship between the development (education) of employees, motivation and performance related to each other has been described. However, in order to benefit from mutual influence of these areas of employees' behavior and acting, it is needed for organizations to dispose with employees who have the necessary potential, which can be partially identified by their observable working behavior. This observable behavior is a manifestation of the achieved competences, which can be e further developed, but only to the extent that the employee's potential allows. The research focused on important areas of human resource management, recruiting, and retaining employees, which form the basis for ensuring the employees with the needed potential and competencies.
The methods used in the research have enabled to compare the collected data in terms of the perception of organizational performance issues by different generations and employees at different job positions. The results of the research showed the importance of mutual communication and knowledge about opinions and preferences of different generational groups of employees but also the importance of the interest of management in understanding the perception of organizational performance by employees at other, maybe lower positions. The analysis of the research results based on the research question 1 revealed important information that employees at lower positions perceive worse the organizational ability to recruit and retain the necessary employees than do employees at managerial positions. In doing so, production employees have a worse perception of the organization's ability to recruit and to retain employees, closely followed by administrative employees.
Limitations of the research were that only perceived organizational performance and only selected issues of perceived organizational performance were analyzed. This allowed only limited analysis and testing. The limitation of research can be also that statistical processing and evaluation of the collected data has a descriptive character, which is caused by the formulation of research questions and research hypotheses. The limitation of the research may be also its geographical limitation, since it was carried out only in the Slovak Republic.
The research presented in this paper was mainly focused on the analysis of perceived organizational performance issues with regard on various generational groups of employees in industrial enterprises. Based on the evaluation of research questions it has been shown that different generations of employees have different perceptions within selected issues of organizational performance of the enterprises. It is the ability to attract important new employees and retain important employees within demonstration the organizational performance of an enterprise that is crucial in ensuring the competitive advantage of an organization through competitive human potential. If employees feel that an enterprise is unable to attract and retain important employees, it may negatively affect its perception and commitment to the organization and their performance provided.
From the overall evaluation of the data for the analyzed issues, it can be argued that most employees stated that the ability to attract important employees is perceived worse and much worse (50.99%-750 respondents) compared to the sum of options much better and better (48.2%-709 respondents). Therefore, encouraging management of industrial enterprises to focus on social activities and activities at local communities, with an emphasis on attracting important employees who are key to the organization's prosperity, as part of sustainable human resource management. One way is to develop sustainable, functional business strategies that focus on succession and use of the internal labor market in human resource management. One possibility is to develop sustainable, functional business strategies that focus on succession and use of the internal labor market within human resource management. Another option for declaring an organization's commitment in the social area is to introduce outplacement programs into business practice.
The analysis of the research results based on research question 2, revealed differences in perception of workplace relationships. A significant finding of presented research is that the variable relationship between managers and other employees was perceived positively throughout the research group. Employees perceived worse and much worse the relationships which was declared by 577 (39.23%) of respondents on the other side 880 of respondents which makes a total of 59.82% that perceive relations between managers and other employees better and much better. Improving the perception of this organizational performance item can be enhanced by maintaining effective communication between employees and management. This highlights the importance of the manager in influencing the employee satisfaction. Relationships between supervisors and employees are influenced to a large extent by the management methods and also the managerial skills of the supervisor. Therefore, it is important to develop and consolidate them through building a suitable organizational culture.
Generally, within the whole group of respondents it is possible to consider relations among employees in general as better and much better where 10.40% respondents indicated the mentioned possibilities, which makes a 70.70% share of all respondents. On the other hand, 420 respondents think that relations between employees are worse and much worse, which makes 28.55% of all answers. Testing the research hypotheses identified a significant difference in the perception of the issue of organizational performance relationships between employees in general, where it was confirmed that members of different generations perceived relationships differently.
We recommend considering the aspect of generational diversity in the management of industrial enterprises, which is often neglected at present because management in industrial enterprises does not address human resource management conceptually, but only on the level of the application of management methods and practices. Testing the second research hypothesis revealed a significant relationship between the organizational performance variable the relationship between employees in general and the ability to retain important employees. Based on the above, we recommend that the management of industrial enterprises focuses their sustainable human resource management strategy on retaining important employees with an emphasis on improving workplace relationships that are demonstrably linked to job satisfaction, motivation and performance achievement. Based on the above, the authors of the paper intend to extend the research in the future to the field of exploring the interrelationship of generational diversity, sharing knowledge and performance management. The authors of the paper plan to test their functional model in the context of various aspects of generational diversity, but also of intergenerational cooperation. Finally, there is a plan to implement the obtained results in industrial enterprises of various sizes in order to prove the applicability of the model for all types of industrial enterprises and its importance for individual fields of sustainable human resource management.