XP is a code-oriented, light-weight software engineering methodology, suited merely for small-sized teams who develop software that relies on vague or rapidly changing requirements. Being very code-oriented, the discipline of systems engineering knows it as approach of incremental system change. In this contribution, we discuss the enhanced version of a concept on how to extend XP on large scale projects with hundreds of software engineers and programmers, respectively. Previous versions were already presented in [1] and [12]. The basic idea is to apply the "hierarchical approach", a management principle of reorganizing companies, as well as well-known moderation principles to XP project organization. We show similarities between software engineering methods and company reorganization processes and discuss how the elements of the hierarchical approach can improve XP. We provide guidelines on how to scale up XP to very large projects e.g. those common in telecommunication industry and IT technology consultancy firms by using moderation techniques.