4D linking versus schedule generation
| 4D linking (TimeLiner, Synchro) | Sensali |
|---|
| Requires an existing schedule | Yes, it is the input | No, the schedule is the output |
| Primary purpose | Visualise and communicate a sequence | Produce a dependency-correct sequence |
| Model use | Geometry attached to activities for playback | Geometry, hierarchy, containment and connectivity read to derive logic |
| Activity creation | Manual, by a planner in P6 | Generated per unit and per process area |
| Relationships | Inherited from the schedule you supply | Generated with type and lag from construction methodology |
| Resources | Inherited | Crew sizing from project staffing data at 1:1 |
| Output | Simulation and rule based links | Primavera P6 XER file, ready to import |
The two are complementary. A generated schedule imported into P6 can be linked straight back into TimeLiner or Synchro for simulation, and the linking is easier because activities already carry a process area structure that matches the model.
When a 4D tool is not the answer
- The schedule does not exist yet and writing it is the bottleneck, not viewing it.
- Manual sequencing takes weeks per facility and is repeated for every system.
- Two planners produce two different schedules from the same model, and nobody can prove which dependencies are real.
- Every model revision forces the schedule to be reworked by hand before it can be re-linked.
Compared with the manual process
The conventional path is a planner reading drawings, deciding what depends on what, re-keying tags and quantities, then typing activities into Primavera P6. Sensali replaces the extraction, reconciliation, area assignment and sequencing steps with one pipeline, measured at 98.8% accuracy on automatic process area detection across four full facility models, producing 220 activities and 190 relationships to date.
Read next
The full pipeline is described on Navisworks to Primavera P6, the sequencing rules on construction sequencing automation, and the file format on Primavera P6 XER export.