Ask HN: How to simulate and rescue a complex project

I am involved with a large Construction Project (5 Hotels Project) that has been plagued by the typical large Project Complex (behind schedule, cost overruns etc.. Current planning using Primavera (Gant Charts have failed to capture the complexity of the Project and have become so cumbersome that no-one is really using them). From observations on this Project as well as numerous others both in Construction as well as Software, there is a critical point, where the size of the project tends to cause some sort of emerging properties that cause all these inefficiencies.

I am trying to get ideas as to how to simulate it. Most people simulate activities (systems approaches fall into this), but my intuition is that I should be simulating people and not activities. Some sort of cellular automata idea. Another observation is that the project history - in a way has properties similar to those of traffic, with work slowing down without anyone really realizing the reasons behind it.

I am looking for ideas out of the box, links any research you might have come across. It is really not much different from Software Engineering.