Construction System Design
Thiết kế biện pháp thi công
Model formwork, scaffolding, tower cranes, and temporary structures. Use virtual mock-up to verify complex construction sequences before field deployment.
Common tools
Tekla Structures, Revit (temporary works), Navisworks
Value delivered
Critical for complex structural systems (special slabs, flat slabs, transfer floors)
Adoption in Vietnam
Applied in steel building and large precast projects. Major Vietnamese contractors use it regularly.
Level of Information Need (LOIN)
G = Geometry · A = Alphanumeric · D = Documentation (ISO 7817-1:2024 method). A blank cell means this use sets no specific requirement for that discipline/stage.
| Discipline | Concept | Schematic | Developed | Technical | As-built / Operation |
|---|---|---|---|---|---|
| Architecture | — | — | — | G3·A2·D1 | — |
| Structure | — | — | G3·A1·D0 | G4·A2·D1 | — |
| Mechanical | — | — | — | G3·A2·D1 | — |
| Electrical | — | — | — | G3·A2·D1 | — |
| Plumbing | — | — | — | G3·A2·D1 | — |
Critical stages: Developed · Technical
Rationale: Biện pháp thi công: means & methods, virtual mock-ups, formwork, falsework, shoring. STRU-led: G3 at ST3 for design concept; G4 at ST4 because temporary structures require fabrication-grade detail. A2 at ST4 for material specification and load-bearing data. Other disciplines at G3/A2 for installation-method sequencing. D1 links method statements.
What it really is
Construction System Design is the modelling of temporary works that support construction — formwork, scaffolding, shoring and bracing systems, working platforms, and specific methods such as jacking or launching systems, suspended platforms, and crane climbing frames — as BIM objects kept entirely separate from the permanent structure model. Unlike building a nice-looking 3D shape purely to illustrate a method statement, this is an engineering deliverable that must pass a load-bearing check: temporary works carry a construction load combination — fresh concrete pour load, wind, live load from workers and materials, vibration from plant — quite different from the permanent building's service loads, and the temporary system itself can lose stability under vibration or cyclic loading if its connections and anchorage are inadequate. The temporary works model must be checked for clashes against the permanent structure, MEP systems being installed, and construction plant (cranes, hoists) before anything is erected on site — fixing a clash in the model is far cheaper than dismantling and re-erecting real scaffolding. This use differs from Site Utilisation Planning (site_utilisation) — which handles crane, storage and site-office positions at the overall layout scale — and from 4D Phase Planning (phase_planning_4d) — which handles construction sequencing over time: construction_sys_design handles the structural engineering of each specific temporary system, taking inputs from both rather than duplicating their content. Because temporary works are tightly coupled to what actually happens on site and are frequently adjusted in the field, the model only has value when kept in sync with the method currently in use, not as a one-off approved drawing filed away.
When to use
Worth the modelling effort when the permanent structure is complex — long-span flat slabs, post-tensioned slabs, transfer floors, steelwork, or heavy precast elements — where the temporary shoring carries large loads and an error could cause a collapse. Also worthwhile on tall buildings needing climbing scaffolding or formwork, or on congested sites where temporary works are likely to clash with cranes and access routes. For low-rise buildings with simple structural systems, conventional field-experience methods are usually sufficient and a dedicated BIM model of the temporary works is not strictly necessary.
Prerequisites
- •A permanent structure model completed at an LOIN sufficient to determine loads, anchorage points and shoring positions for the temporary works
- •An agreed construction sequence and staging, taken from 4D Phase Planning (phase_planning_4d) rather than re-derived independently
- •Site layout data (crane positions, access routes, exclusion zones) from Site Utilisation Planning (site_utilisation)
- •A method engineer with the structural competence to design the temporary works — distinct from someone who only models the geometry
- •Manufacturer specifications for proprietary formwork or scaffolding systems where a rented or off-the-shelf system is used
Inputs
Design task team · .rvt / IFC
Structural engineer · .pdf / .xlsx
Appointing party · lead appointed party · .pdf / .docx
Lead appointed party · .nwd / .pdf
Lead appointed party · .dwg / .rvt
System supplier · .pdf / .dwg
Outputs
Temporary works model (formwork / scaffolding / shoring) with a structural calculation report
gốc (.rvt) + báo cáo .pdf → Lead appointed party · supervising engineer
Accepted when: Meets load-bearing requirements under the applicable design standard, signed by the structural engineer responsible for the calculation
Clash report between the temporary works and the permanent structure/construction plant
.pdf / .bcf → Site management team
Accepted when: Lists each conflict with its resolution, not just screenshots
Method-statement drawings and the erection/dismantling sequence
.pdf / .dwg → Site construction crew
Accepted when: Structural calculation signed off by the structural engineer and consistent with the agreed 4D sequence
Change log of the method statement against the approved version
.pdf / bản ghi trên CDE → Appointing party · lead appointed party
Accepted when: Every field change is logged, recalculated and reflected in the model before it is applied
General workflow
Define the preliminary construction method
The method engineer works with the 4D planning team to fix the construction sequence by phase and zone, and identifies which type of temporary system each element needs.
Method engineer · Revit · Navisworks TimeLiner (referencing the 4D sequence) → Preliminary method statement by phase
Model the temporary works
Build parametric objects for formwork, scaffolding, shoring and working platforms, attaching dimensions and design loads to each element — not simple massing without data.
Temporary-works modeller · Revit (temporary works modelling) · Advance Steel (steel temporary systems) → Discipline-level temporary works model
Run the load-bearing check
Run a structural analysis of the temporary works under the construction load combination. This is the step most often skipped in practice, and the direct cause of most temporary-works collapses.
Structural engineer · Autodesk Robot Structural Analysis Professional → Temporary works structural calculation report
Check clashes against the permanent structure and plant
Load the temporary works model together with the permanent structure, MEP systems being installed, and construction plant into one federated model to detect geometric conflicts before anything is erected on site.
BIM Coordinator · Navisworks Manage (Clash Detective) → Temporary works clash report
Approve the construction method
Submit the drawings, model and calculation report to the site manager and the safety team for sign-off before erection is allowed; keep the approval on the CDE for later reference.
Site manager · safety team · Forma Data Management (CDE) — approval workflow and audit trail → Signed-off construction method statement
Erect and supervise on site
Erect the temporary works exactly as approved; the site supervisor checks the as-built condition against the model during erection using an inspection checklist.
Construction crew · site supervisor · Field inspection checklist (paper/digital form, not a modelling tool) → Erected temporary works with an inspection record
Update the model when the method changes on site
Any deviation from the approved version — a different prop spacing, anchorage position, or system type — must be logged, recalculated and reflected in the model before it is applied, not built from a verbal change and documented afterwards.
Method engineer · structural engineer · Revit · Autodesk Robot Structural Analysis Professional → Updated model and calculation report
Diagram
↺ The temporary works model is a living document tied to the site, not a drawing approved once and filed away
Common pitfalls
Scaffolding or formwork deforms, settles or collapses during a concrete pour or under construction load
Cause: The temporary works were modelled only to illustrate geometry, with no structural analysis run for the real construction load combination
Fix: Require a structural calculation report signed off by the structural engineer before erection is allowed, not just a good-looking 3D model
The temporary works clash with the permanent structure, MEP being installed, or the crane's travel path during construction
Cause: The temporary works model was built in isolation, with no clash check against the permanent structure and site layout before going to site
Fix: Load the temporary works model into a federated model with the permanent structure and construction plant to detect conflicts before erection
The approved method drawings no longer match what is actually being erected on site
Cause: The method was changed verbally in the field — different prop spacing, different anchorage — without updating the model and the calculation
Fix: Require every method change to go back through calculation and model update before it is applied, with the change logged on the CDE
Work is duplicated or dropped between the teams responsible for site layout, scheduling and construction methods
Cause: The scope boundary is not defined: site_utilisation covers crane and storage positions at the layout scale, phase_planning_4d covers sequencing over time, and construction system design covers the structural engineering of each specific temporary system
Fix: State the scope boundary explicitly in the BEP and use the outputs of the other two uses as inputs, rather than remodelling them from scratch
Measuring effectiveness
Count conflicts found through model-based clash checking, compared with those only discovered on site after erection
Benchmark: no independent benchmark — set an internal target
Elements with a calculation report divided by the total number of temporary-works elements in scope
Benchmark: no independent benchmark — set an internal target
Measure the interval between the date a change is logged and the date the model and calculation are updated on the CDE
Benchmark: no independent benchmark — set an internal target
Legal basis
There is NO specific requirement for construction system design (formwork, scaffolding, temporary shoring) in Decree 217/2026/NĐ-CP — construction_sys_design falls under Article 8 generally, not a distinct statutory obligation. Specifically: Art. 8(1)(a) makes BIM mandatory for new-build works Grade II and above, from the feasibility-study stage; Art. 8(2) assigns scope, content and information requirements — including whether the temporary works are modelled at all, and at what LOIN — to the contract for each stage, which is the only basis for putting this requirement into the EIR/BEP. Technical responsibility for the safety of temporary works — load-bearing capacity, stability during erection and dismantling — sits under specialised occupational-safety law and structural design standards, not within Decree 217. The practical consequence: modelling the construction method is a CONTRACTUAL obligation when the appointing party or contractor chooses to do it, not a separate statutory obligation under Decree 217.
Sources
Only official sources (legislation, standards) and peer-reviewed academic work are cited. No vendor marketing figures or press sources. Reference only — does not replace legal advice.