Higher-level approach generates far more optimization potential, but it increasing complexity of the
system. To find a feasible network configuration and organizational structure, it is necessary to collect all
relevant logistic factors. Not the peculiarities of in-house supply chains, but also interferences between
individual logistic chains and between logistics and the construction processes have to be considered. All
factors are highly variable in regard to type, time and spatial aspects (table 1).
Types of construction requirements for outfitting processes vary mainly in regard to vertical and horizontal
material transport. For vertical transport cranes are predominant. Elevators, lifting platforms and
high lift trucks are also alternatives to be considered. Horizontal transport can be facilitated by forklifts
and transport containers on wheels. Pumping allows for both, horizontal and vertical transport. Manual
transport, especially at small scale, is also common for outfitting processes and currently counts for a
quite a big portion of overall working time.
Spatial variability is indicated by alternative positions of construction requirements. In comparison to
structural work, the working areas during outfitting processes are literally scattered all over the building,
because innumerable working positions are feasible. Furthermore, and especially in outfitting, the rescheduling
of storage areas, the rearrangement of means of transportation and other major changes in layout
are daily business. Often even the ways of access to the site is change. These changes are mainly caused
by the work process itself. For example an unfinished room is first used for material storage, but has then
to be made free for outfitting processes, which shell start in this room. A stairway is temporarily blocked,
because of ongoing finishing works.