Tunnel construction is similar to building construction in that
activity durations and logic define the construction schedule.
However, the activities that control progress for tunnel construction
projects are linear in nature; thus, the scheduling model cannot uccurately be represented by the conventional critical path method.
The critical path method is not effective in monitoring progress
and forecasting project completion for linear-type construction projects.
The critical path method can monitor this production but lacks
the ability to show relationships among activities. Combining the
two methods produces a practical scheduling tool for tunnel and
other linear-type projects.

This paper focuses on the implementation process and the value
in using a combined qproach, using an example tunnel project as
an illustration.