The development of large scale software systems is a complex and lengthy activity. In the development of large scale systems different types of stockholders (e.g. customers, system users, system analysts, designers, and software developers) have to take part and work with one another. Requirement engineering is considered to be the most important activity in the development of software systems [6]. If the system under development is a large and complex system, then the importance of the requirement engineering becomes even more important and necessary. There are many problems and challenges that the development organizations are facing in the requirement engineering phase for large scale systems. The software engineering community is working day and night in this area and they have proposed many solutions and lessons for addressing these problems and challenges faced. This paper presents the main contribution of the research work that have been conducted in recent years to identify the requirement challenges faced in large scale development systems and proposed lessons learned addressing these challenges. In this paper we have presented two challenges that were observed by us in [LSS] projects. This paper also identifies issues and questions which are still open for further research and thus it will serve the future researchers as a guide map for doing research in requirement engineering.