By 2025, there will be four different generations in the workplace. Different generations have different work values, motivational drivers, working and learning styles, communication preferences and approaches to technology. While on the one hand, multi-generational teams offer a richer way of looking at work, on the other hand, they ask to rethink the managerial role, redesign HR practices and reinforce collaboration skills. Let's have a look at who these four generations are. Born between 1946 and 1960, baby boomers are famous for their idealism combined that with a competitive spirit. They were teens in the '60s and '70s, a period of widespread discontent, revolutions and battles. At work, it's a generation that is characterized by strong dedication and spirit of service. Baby boomers are oriented towards reaching goals and professional success. They're willing to sacrifice and work a lot. They are loyal to the organization and respect the rules, despite being skeptical of authority. Born between 1961 and 1979, the members of Generation X are known for an orientation towards results and attention to work-life balance. They were teens in the '80s and at the beginning of the '90s, in a period that was calmer, but also ambiguous and uncertain. They grew up fast. They spent a lot of time by themselves, without their parents, and with the idea of relying on their own efforts. Due to these experiences, they wish to have control over their own lives, to be good parents, to cultivate friendships and manage their own time. At work, they're conservative and oriented towards results and efficiency. Because, that way, they also gain time for non-work as well. Born between 1980 and 1995, Millennials, or Gen Y, are known as the me-me-me generation. They feel special, they freely express their ideas and criticize most of others'. They seek feedback daily. They're optimistic with regard to the future, that easily becomes also a source of anxiety and stress. The '90s and the 2000s, when they were teens, were marked by dramatic and unpredictable events, that lead Millennials to seek experiences that are fully satisfying because life is potentially short. At work, they seek challenges but they do not want responsibility and they're little inclined to accepting positions that they do not consider gratifying. They want to make a difference rapidly. The youngest generation, which is now approaching the labor market, is the Generation Z, or gamers or iGen, where I stands for individualism, in no hurry, internet, in person no more, inclusive, insecure, and with low intrinsic motivation. Born between 1996 and 2010, at work they will be realist, even disillusioned and much more reliable than Millennials. They look more for a good and secure job than for the dream job and they know they will have to work hard for it. They have reasonable ambitions. They look for equity and clarity with regard to their career and development. They need guidance and frequent and sure feedback, not trusting themselves enough. All these aspects highlight the crucial role that HR management will play in the future of international organizations in order to attract, retain, and then engage different generations at the same time. Specifically, international organizations nowadays are facing five challenges. The first one is the attraction of young talents and generalists. International organizations have become famous for their several pages long vacancy announcements. They tend to hire mid-level professionals who have strong, specialistic knowledge, while overlooking young talents and generalists. Internships do not normally lead to jobs. Starter programs like the JPOs, or informal entries, through individual consultancy contracts are the only ways for young professionals to get into international organizations. Graduates are often suggested to accumulate experience somewhere else and then apply for low-level positions few years after. How many talents do we lose along the way? What is the potential loss of entrepreneurship and energy? Compared to other organizations, international organizations may lose competitiveness on new generations who expect clarity, linear career paths, and guidance since the beginning. The second challenge relates to the inter-generational equity and the difficulty of a fluid social contact in the workplace. With the new public management reforms hitting the international organizations throughout the 2000s, the rules of the game changed fast in order to incorporate the expectations of geographical and functional mobility within the organization, in order to adapt the high-level uncertainty, provide short-term contracts to remain in the system. Yet, these new rules apply to the younger generations only, while the older ones have continuing contracts and limited expectations of mobility according to the traditional public sector employment rules. This requires greater attention to inter-generational equity, especially because the incumbents, like Millennials, or Gen Z, are characterized by a strong sense of perceived equity and fairness. The third challenge deals with job content, sense of achievement and transformational careers. The inter-generational cultural transformation entails the need for less bureaucratic, sealed jobs and thrives to make a difference, especially for Millennials. International organizations are working on enabling transformational careers, reforming the internal administration. By doing so, they demonstrate dynamism, closeness to the cause, and entrepreneurship through job role design and workload allocation patterns. Hopefully, this will allow for retaining and engaging younger generations that look for learning and career opportunities. The fourth challenge is about value-based transformational leadership. The new generations often raise the fact that their managers are great senior professionals with a transactional leadership approach. In other words, they tend to pay less attention to motivating others and to coaching direct reports and their teams. International organizations are now putting tremendous attention on transforming managers into effective leaders and that's a fundamental element that young generations expect to find in the workplace. Now more than ever, people do not leave organizations, they leave managers. The fifth and last challenge deals with exploiting the potential of the youngest generations to embrace the future of work. Only in recent years, international organizations have become more digital. This delay may be linked to a hierarchical way of doing things, which often limits the efforts of the younger generation to change how things are done. Indeed, the gamers are the ones that can support international organizations to use technology at its best. While in the traditional model of international organizations your voice is proportional to your role, in modern ones, you can expect a true, 360 model that will systematically empower the young generations in experimenting how to integrate technology in all aspects of the organization. This requires inter-generational trust, a reasonable risk-taking approach, and a reduced power distance. These are the key challenges of managing a multi-generational workforce in international organizations, taking also into account public service motivation models.