  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.
