**1. Introduction**

E-skills are very importance in this new age, for job applications, communications, online booking, banking, and ordering, as well as completing online courses. Today, businesses face many challenges such as sustainability, globalization, and the development of new technologies. The electronic evolution has affected all organizations and its influences continue to grow. Internet use has had an impact on all business process, including communication [1] (p 94). Globalization has changed the way people and communities relate [2] (p1). The Internet has the ability to change and influence many activities and fields and enables people to live and work wherever they desire [3] (p 3), becoming sustainable and obtaining sustainable performance. Employees who are involved in sustainable activities and adopt sustainable development principles, become sustainable human resources [4]. Today, the challenge is not related to how to implement new technologies but how to acquire new e-skills, use them properly and sustainably, and combine them with other channels of communication. On the basis of these reasons, the scope of this research is to use simulation and mathematical modeling to show that there is a positive and very strong relationship between sustainable HR development and Internet use, which leads to an increase in the e-skills and e-activities mentioned above. The correlation function and

Excel data analysis were used for the analysis and comparison among the three established zones (Romania, average level at the EU28 level, and the best-in-class group), and demonstrated that there is a relationship which shows the future trends on the European level, therefore, helping specialists increase skills, overcome risks, make better decisions, reduce costs, and increase performance. Some research hypotheses were established such as there is a correlation and a strong and positive relationship between e-skills and some e-activities developed in the new digitized world.

Many studies have been carried that studied the sustainable development of a performance organization [5,6] (p 202 and p 89) and the role of training e-competencies for competence jobs, for competence programs, to improve HR training and development, or to map processes [7] (p.120), [8] (p.1459), [9–11], [12] (p.1), however, these studies did not analyze the relationship between the e-skills and e-activities in order to obtain sustainable performance. Thus, the novelty of this study is important to others as well as the specialists in the field. The study is organized as follows: Section 2 presents a literature review and an explanation of the existing factors that influence sustainable development including the trend of Internet use, as well as the importance and evolution of e-skills, digitization, and e-activities; in Section 3, the research methodology is presented, in Section 4 the framework for the analysis of the relationship between the variables through the prism of the correlation between the three zones and Excel data analysis, and the results obtained by implementing the correlation matrix on the level of the three zones; and in Section 5 the discussion and conclusions are presented.
