Tracking Critical Path

Hi all,

This is my first post on Planning Planet so I'd like to introduce myself. I'm working on a multi high-rise project in Brisbane, QLD, Australia and although I have a few projects under my belt, this is my first job as Project Planner. We use Primavera P6 V7 Project Management here and I am basically required to plan and schedule two programmes - a client-issued programme and a subcontractor-issued programme.

The programme includes procurement, design, construct (substructure and superstructure), fitout and handover. Currently we are mid-way through substructure and I am having some trouble tracking the critical path. Depending on how I relate / lag the foundation piling with bulk excavation and the retention system, the critical path seems to "disappear" until fitout begins. As a remedial fix I have included links to Finish Milestones with finish constraints so that subcontractors still see a critical path on their weekly month-lookahead programme issue. However, I think this is a bit of a bandaid fix, but I can't seem to find any errors in my logic that are causing the critical path to disappear. Can anyone suggest what I can try to get a critical path running through the project? It's obvious what the critical path is on-site, but I want to reflect this in the programme (particularly as we have had a LOT of rain in recent months and EOT's are coming in left right and centre).

Kind regards,

Reece