The Model-First Principle
In Tekla Structures, all drawings should be extracted from the model — never drawn independently of the model. When dimensions on a drawing are extracted from the model geometry (using Tekla's associative dimensioning), they automatically update when the model is changed. When dimensions are typed manually on top of the extracted drawing, they become disconnected from the model and can be out of sync after the next model change.
Change Management — Keeping Model and Drawings in Sync
Every time the structural model is modified, the associated drawings must be regenerated or verified. Tekla flags drawings that are 'not up to date' relative to the current model state — these flags must be resolved before any drawing is released. A common error is issuing a drawing that was extracted before the last model modification, without regenerating it. The drawing still shows the old geometry; the CNC file shows the current geometry. The resulting inconsistency is not caught until a hole doesn't line up in assembly.
Model Audit Before Every Submittal
Before each major submittal, run a model audit covering: all members have section profiles assigned, no duplicate piece marks exist, all connection components reference valid model objects, all drawing links are current, and BOM quantities match drawing counts. A 30-minute audit before a 100-drawing submittal eliminates a category of errors that EORs flag in first review cycles and that damage the detailer's credibility.
Manual Overrides — The Primary Source of Inconsistency
The most common source of model-drawing inconsistency is a manual dimension override on a drawing that was never updated when the model changed. In Tekla, a manually edited dimension becomes a static text value — it no longer updates when the model geometry changes. When the next model revision shifts a hole group by 1/4", the extracted drawing dimension updates; the manually overridden dimension does not. The best practice is to never manually override dimensions. When a drawing dimension appears incorrect, fix the model geometry — do not fix the dimension on the drawing.
Multi-User Model Environment Controls
On large projects with multiple modelers working in the same Tekla model simultaneously, consistency requires clear work breakdown assignments. Two modelers working on adjacent connections without defined ownership can create conflicting geometry — one modeler's connection overrides another's, producing inconsistent hole patterns between the mating members. Tekla's multi-user model environment uses read-write access control to prevent simultaneous edits to the same object, but work area ownership must be managed actively. Weekly model coordination meetings between modeling team leads are standard practice at Tectonix on projects with more than three simultaneous modelers.
- Work area assignments by gridline or floor — documented at kickoff
- Read-write access control for simultaneous users
- Daily model backup before each shift begins
- Clash and consistency check run every morning before production starts
- Drawing regeneration as the final step before any submittal package is assembled
The QA/QC Drawing Check as the Final Inconsistency Filter
Even with all model controls in place, a human QA/QC check remains the most reliable filter for model-drawing inconsistencies before submittal. The checker should compare selected drawings against the 3D model view — not just read the drawing in isolation. Specific items to verify in this check: connection plate dimensions on the drawing match the model geometry; weld symbols on the drawing are consistent with the connection component used in the model; piece marks on the drawing match the piece marks in the model's BOM; and the BOM entry for each member matches the section shown on its detail drawing.