3D ENABLED LEAN

CONSTRUCTION

FASTER, BETTER, SAFER,

AND LESS EXPENSIVE

PROJECT DELIVERY

PROJECT CHALLENGEOwner’s goals of faster, better, and less expensive construction are difficult to achieve using conventional 2D paper-based delivery systems, with owners often forced to pick only two goals.

The Design/Build (D/B) team on this project was presented with the challenge to not only design and deliver a 455,000 SF manufacturing facility under an extremely fast-tracked schedule, but also to reduce the final cost of the project by over 15%, while maintaining highest standards of quality and safety during construction.

Fully coordinated systems in 3D before construction.

30/11 - 28/1A/E Phase

4/5 - 30/6Steel Fabrication , Erection ...

30/1 - 12/2Bidding – Steel Fabricator

15/2 - 3/6Steel Detailing , Shop Drawing Review

30/11 - 1/1Design /Analysis

5/12 - 29/1Drawings /CDs

10/2 - 30/6Steel Detailing , Fabrication , Erection

2/4

Mill Order8-14 Weeks (Typical)

Steel Mill Order required within 3 Weeks

SCHEDULE

The D/B team was required to deliver the facility in less than 40 weeks from the start of design. A comparable fast track design/bid/build could have required approximately 60 weeks from design to project closeout while, conventional design/build approach would have required approximately 50 weeks.

One of the most critical dates was that of ordering the 4500 tons of steel from the mill. Typically, the A/E would require between 8-14 weeks for completing and issuing mill order drawings to the fabricator. However, this would have missed the mill rolling cycle and delayed the actual steel delivery by nearly six weeks. In order to meet the mill-rolling schedule the mill order needed to be issued within 3 weeks of the start of design.

From the beginning, the entire D/B team understood that this project could not be delivered on schedule and within budget if the team was to use conventional delivery systems and methodologies.

Comparison between Design/Bid/Build & Conventional Design/Build Schedules

Steel delivery schedule – Accelerating the steel mill order to 3 weeks

Conventional Design/Bid/Build (80+weeks, 60 Weeks if fast tracked)

Conventional Design/Build (60+weeks, 50 Weeks if fast tracked)

Design Design GC Bids GC Construction Field ChangesReviews Awd

18 3 4 2 55 4

12 48 1

Design Construction Field Changes

ELEMENTS OF SUCCESSThe D/B team understood that 3D BIM alone is insufficient to deliver the project on schedule and within budget. Advanced planning, supply chain project management, and team commitment to apply lean principles were critical factors for the project’s success.

The lead Architect/Engineer (A/E) had a dedicated advanced technologies group that took the lead in applying lean construction principles and 3D-enabled delivery for eliminating wasteful practices especially at handoffs between design, detailing, fabrication, and installation phases.

“Kaizen Events,” a lean concept, were used at various stages of the project to streamline workflow. Kaizen Events are short and focused sessions that include value stream mapping, analysis, and workflow re-engineering aimed at eliminating non-value adding activities.

Fully coordinated systems in the model resulted in highly organized construction site during installation.

COLLABORATION

Key members of the D/B team including the A/E, sub-contractors, and the owner’s engineering team co-located at the offices of the General Contractor for approximately 3 months. At this co-location center, the D/B team worked closely to clarify project objectives, define scope, and fully coordinate the design prior to construction.

As design decisions were being made, they were incorporated in the A/E’s 3D design models and reviewed with the D/B team for cost and constructability.

Key team members from various companies co-located at the offices of the general contractor to accelerate decision making.

STRUCTURAL STEEL

To meet the 3-week mill order date, a Kaizen Event was used to eliminate wasteful activities inherent in 2D paper-based delivery at handoffs between the A/E and the fabricator. The A/E and the fabricator agreed to utilize intelligent 3D model exchange. The A/E’s 3D analysis model was transmitted directly to the steel fabricator. The model was imported into the detailing software and steel quantities were extracted directly from the 3D model. Early availability of this data also allowed the fabricator to provide timely input to the A/E regarding member sizes, resulting in additional savings to the project.

Because of BIM, the key mill order date of 3 weeks from the start of design, was met and the fabricator was able to start the detailing process early.

Key Steel Dates:1. Detailing began 11/10/20042. Detailing completed 2/14/20053. Fabrication began 11/24/20044. Fabrication completed by 4/15/20055. Erection began 2/28/2005 6. Estimated steel completion date 6/30/2005

The fabricator submitted weekly up-to-date steel 3D models to the A/E. The distributed to the D/B team for coordination.

Steel Delivery Value Stream – Eliminating Waste at Handoffs and Use of Steel Interoperability

The fabricator used 3D to detail the steel and control the fabrication and erection schedules – 3D models were kept up to date throughout construction.

A/E: Issues 2D mill order 3D Model & IFC drawings to steel fabricator (for record).

Automatic BOM for Mill Order Manual takeoffs ~ 1-2 days.

Import Design model data into fab. software ~1-3 weeks savings vs. 4-9 for manual input.

Steel Fabricator Constructs 3D Manufacturing Detailed Model

A/E 3D Analysis or Design Model

Steel Fabricator Extracts Shop Drawings for Engineering Review/Approval

Analysis & design interface.

Model and issued for construction documents interface.

-- Savings due to reduced markups and reviews

On-board review of shop drawings using 3D Model

Reduced quantity of shop drawings for review

Direct exchange of

A/E model to steel

fabricator

Import steel fabrication model into A/E design model

(as-built)

MUILTI-DISCIPLINE COLLABORATION USING BIM

The team had its first multi-discipline coordination meeting on 11/11/2004 and continued this process weekly through 2/28/2005. A Kaizen Event was used to eliminate waste in the design, detailing, and fabrication of the architectural and MEP systems.

The D/B team and the owner agreed that the traditional 30/60/90 paper-based review would be replaced with weekly on-board reviews of the 3D model.

Mar. 11, 2005 session0 interferences

Install-level collision free 3D model was issued for construction – thousands of interferences resolved during coordination.

MUILTI-DISCIPLINE COLLABORATION USING BIM

The team resolved thousands of interferences. All issues that could have affected the structural steel erection to the steel fabricator ahead of the erection schedule.

On 3/11/2005, the final 3D models and associated 2D documents of architectural and MEP systems were released for construction.

Issues that may have impacted steel erection were detected and resolved before the steel construction schedule.

BUILDING TO THE MODEL

The final 3D models were fully detailed to installation level, which allowed the sub-contractors to maximize the benefits of off-site fabrication and pre-assembly. By delivering Just In Time (JIT) to the construction site, the time spent at the construction site was significantly reduced.

Field crews were instructed to install all systems according to the 3D models and associated construction documents.

At times during installation, install crews had to trust that the model as they were required to install systems with many offsets when there were no other systems around. The conventional wisdom of first in takes the space did not apply, as the 3D model took into account space requirements of systems that are yet to be installed.

HVAC value stream – 3D design models were shared with the sheet metal contractor who refined those models to install level then used to drive the CNC cutting equipment. HVAC was installed with zero changes in the field.

Piping systems were installed with offsets to accommodate space requirements for

other systems that will be installed 4 months later

Direct interface from fully coordinated 3D model to CNC machines

Installation drawings from 3D Model.

Fully coordinated HVAC model with steel and other MEP systems

Offsite fabrication

JIT delivery & installation without field changes

Potential to reduce raw material by up to 20%

BUILDING TO THE MODEL

The 3D model included not only space requirements of the physical building components, but also maintenance requirements. Components were installed to very tight tolerances (less than ½”) and checked for compliance during construction.

As a result, the owner had access to an as-built 3D model of the entire facility prior to construction which was used to accelerate the coordination of the process systems inside the facility.

Above – equipment modeled with maintenance requirements to detect and avoid code violations

Right – 3D models helped identify and produce unconventional solutions at the expansion joint.

Trusses were replaced with deep beams to maximize openings for MEP routing.

BIM SOFTWARE AND INTEROPERABILITYThe team used several best-in-class software applications to construct the various models of the facility including:

RAM Steel SDS2 detailing software Bentley ArchitecturalBentley StructuralBentley MechanicalDesign SeriesBentley Interference ManagerBentley NavigatorQuick Pen (piping)IntelliCAD (sheet metal)NavisworksBentley ProjectWise collaboration servers

The sheet metal fabricator used the 3D models to drive the CNC equipment to cut and fabricate the ductwork. The piping contractor was able to deliver piping components at exact lengths to the construction site.

The D/B team relied on Navisworks and Bentley Triforma’s capabilities to interface with a wide variety of CAD formats to integrate all facility systems and resolve design interferences.

MEP/Steel Construction & Installation Documents

4D Construction Sequencing

Procurement (BOM)

As-BuiltVerification

Plant/Process Integration

Structural Steel, Detailing,

Fabrication

Architectural

Structural HVAC

Piping

Electrical

Layout/Process

Electrical/Steel

MEP

BREAKTHROUGH RESULTS

The construction site was remarkably quite and organized. Construction crews rarely overlapped and dumpsters remained empty during construction due to increased use of offsite fabrication, pre-assembly, and JIT delivery.

Structural steel erection was completed 35 days early. There were no changes to structural steel during installation.

MEP systems were installed without any field rework. Installation of piping and HVAC systems was completed during the first few months of construction.

Sub contractors were able to produce detailed quantity takeoffs and order material exactly as required.

Eliminating field changes improved site safety. Movement of people and material were also reduced contributing to increased safety factors.

Overall cost was reduced by 3- 5% due to interference avoidance.

Eliminating field changes improved morale. Workers took pride in their work by knowing they were installing it right the first time.

The project was delivered to the owner almost 5 weeks ahead of schedule (15% accelerated) with virtual no field overtime.

RETURN ON VALUE

Using 3D BIM on this project was an investment by the entire design, fabrication, and construction supply chain in both technology and time to critically review and revise conventional workflow. This investment translated to win-win-win result and significant savings to all project participants and the owner.

As the second in a four project series utilizing 3D enabled lean construction across the design/fabrication/construction supply chain, this project has provided real project metrics that 3D BIM can deliver projects faster, better, safer and at lower cost than conventional 2D paper-based approaches.

Above, photo of site and 3D model overlayBelow Left – piping components were pre

assembled and lifted into placeBelow/Right – construction site reduced

need for lay down areas.