Engineers working in expatriate situations experience intra-project-team cultural diversity and therefore need to develop cross-cultural abilities. In culturally diverse project teams the cross-cultural adaptation process is a significant contributor to project success. This paper identifies the challenges faced by Indonesian expatriate engineers in the cross-cultural adaptation process in multicultural working environments. This paper shows the factors that influence the adaptation process of the engineers' working situation in performing systems engineering practices in multicultural work environments. We report the results of interviews with 18 Indonesian engineers working outside Indonesia in multicultural teams concerning their experience and knowledge of cross-cultural adaptation in the implementation of systems engineering practices. The engineers were working in seven countries in the Middle East, South East and East Asia and Australia. The results indicate three factors that influence the cross-cultural adaptation process in culturally diverse project teams: previous experience, workmates influence and cultural dimension.