BIM to support DfMA & Lean Construction

Proposed Activity

Richard Kelly, buildingSMART International

Agenda

• What is DfMA (Design for Manufacture & Assembly)?• Benefits delivered through DfMA• DfMA links to other initiatives and enablers• Issues holding back universal adoption of DfMA• Discussion

• how can open sharable BIM standards enable DfMA?

What is DfMA in the Built Environment?

What is DfMA in building design?

• DfMA: developed since the 1970s in several industries• Led by US National Science Foundation,

Salford University, IBM, Xerox, Ford, GM, Lucas & others

• DfMA is the combination of Design for Manufacture (DfM) and Design for Assembly (DfA)

• It is a structured process• It is a primary driver of reduced lead

times, whole life cost and quality improvement

Image courtesy of Heathrow Ltd

Designing for Manufacture

• Understand manufacturing processes, capabilities & cost drivers

• Select materials & processes• Estimate cost of designs

suggested by the DfA stage• Refine designs, model, simulate

and prototype

A new lounge designedwithin manufacturingcapabilities of steel and panelised systemssuppliers

Image courtesy of Heathrow Ltd

Designing for Assembly• Does a part need to move

independently of others?• Does the part need to be made of a

different material or be isolated?• Does it need to be separate to

enable assembly of other parts?• Would combining it with others

exceed limitations for transport or lifting?

• Does the part’s assembly time exceed the time allocated in the build rhythm?

If “No” to any of these look to combine it with other components or eliminate it

BEFORE

AFTER

Source: Boothroyd, Dewhurst & Knight Source: BAA T5

BEFORE

AFTER

Source: Boothroyd, Dewhurst & Knight Source: BAA T5

Modularity & mass customisation

Image courtesy of Heathrow LtdModularity definitions from Joseph Pine II, Mass CustomisationHavard Business School Press

DfMA in summary

• A way of looking at the whole facility or product and determining the optimal way of making the parts and assembling them

• Applies equally to on-site & off-site• A methodology that the (whole) design team needs to

engage with• Can be applied to bespoke buildings or mass production• An enabler of “mass customisation”

Benefits of DfMA

The objectives of a DfMA approachThe optimised design enables a more efficient build phase.• Cost less• Schedule duration less• Quality and maintainability improved• No of site trades less• Impact on operations & the public less• Safety improved

NOT value engineering which is often:• scope reduced• suppliers squeezed

Image courtesy of Heathrow Ltd

Benefits of DfMA

Modular and innovative design combined volumetric and flat-pack solutions.Cost savings through:• Optimised and improved tolerance• Minimised interfaces• Shorter schedule by 75% (100 weeks of stand availability saved)• Factory predictability • Modular standard design• Fewer on site trades – 33,000 hours removed from site• Minimal stand closure (only 2 weeks per stand)

Capex 11% less than traditional build. Opex savings c. £2.5million due to schedule reduction

12 large buildings assembled in a complex, time constrained environment with ZERO accidents

Safety

Quality

WL Cost Time

Courtesy of Heathrow Ltd

Heathrow T5CNodes

Aspects influenced

Procurement

Installation

Operational

Maintenance

Risk

Training

• Less components• Trades offsite• Low level working• Tighter tolerances therefore more predictable fit• Better capabilities• Repeatable processes• Reduced schedule

• Better ergonomics in use (specification & orientation)• Access for maintenance, refurb & renewal

• Optimised decisions for• Maintenance access & frequency• Renewal / replacement access• End of and through life asset failure behaviour

• Visual instructions direct from the design

DfMA opportunitiesDfMA elements

Aspects influenced

Facility / asset life - years

Disposal

Procurement

Installation

Operational

Maintenance

Risk

Training

Opex

Capex

Links to other initiatives

Quicker, Better (Q & CO2), Cheaper (wlv), Safer

Linking the built environment initiatives

DfM

A

Contractual mandate

Lean

6 s

igm

a

Offs

ite

Cap

abilit

y

Some GovernmentsSome clients

Much has been done since “Rethinking Construction” but in pockets of excellence.Linking it together remains a problem.AM

(ISO

550

01)

The goal

Lean constructionDesign for Manufacture, Assembly and Commissioning (DfMA+C)• Determines the constraints• Analyses the build sequence and determine the optimal rhythm• Identifies opportunities for offsite (in lean factories)• Ensures rapid integration for the offsite elements to interface well onsite• Identifies opportunities to eliminate componentsBuild phase establishes lean, continuous flow conditions onsite (& offsite)

Applies to bespoke buildings or mass produced “boxes”An enabler of “mass customisation”

The Traditional vs DfMA approach

Traditional DfMA

Collaboration between trades & disciplines to:• Manage interfaces• Eliminate clashes• Use innovative offsite practices effectively• Reduce components• Provide visual instructions for assembly and

maintenance• Optimise for operational use & maintenance• Predict through life and end of life behaviour

• Different disciplines designed in isolation• Risk managed at company interfaces not

collectively • Risk mitigated through high intensity at build

phase• Opportunities to remove constraints from

project not able to be taken• Whole life value measurement not possible at

the design stage

Improvement in WLC is through reduced schedules and optimised decision making NOT scope reduction or squeezing supply chain margins

Applying a DfMA StrategyStrategy from the supplier is expected to remove wasteful aspects.WORMPITT

14 tools provided for guidance.

1. Commercial considerations – contracts that drive collaboration & flow.

2. Design for productivity3. Design for logistics4. Design for modularity5. Simulation & correlation

(BIM)6. Process capabilities

8. Use of common parts9. Reduce parts10.Reduce assembly risks11.Make fabrication easy12.Make handling easy13.Reduce interfaces14.Efficient methods of

jointingDfMA in Construction Strategy Richard Kelly Nigel Fraser

Collaboration between trades

Progressive application through facility lifecycleConcept Definition Development Implement DisposeHand

overStrategy Operation

Project constraints identifiedBuild rhythm to meet schedule1. Commercial considerations2. Design for:

3. productivity4. logistics5. modularity

6. Simulation & correlation7. Process capabilities

DfMA

8. Use of common parts9. Reduce parts10. Reduce assembly risks11. Make fabrication easy12. Make handling easy13. Reduce interfaces14. Efficient methods of jointing

Facility data

Continuous improvement

DfMA in Construction Strategy Richard Kelly Nigel Fraser

Issues holding back universal adoption of DfMA

Quicker, Better (Q & CO2), Cheaper (wlv), Safer

Linking the built environment initiatives

DfM

A

Contractual mandate

Lean

6 s

igm

a

Offs

ite

Cap

abilit

y

Some GovernmentsSome clients

Much has been done since “Rethinking Construction” but in pockets of excellence.Linking it together remains a problem.AM

(ISO

550

01)

The goal

Linking the built environment initiatives

Some GovernmentsSome clientsMore required

Open data has come of age.• Open standards• Technology• Cohesive

community

The goalQuicker, Better (Q & CO2), Cheaper (wlv), Safer

DfM

A

Contractual mandate

Lean

6 s

igm

a

Offs

ite

Cap

abilit

y

AM (I

SO 5

5001

)

The Procurement dichotomy

Early engagement of specialist• Solution lock-in• Lack of commercial tension• Is the client prescribing the

solution?• Off-site solution that supply chain

can provide efficiently• Reduced schedule duration

Engagement of specialist after scheme design• Non-optimised solution for offsite• Design duration extended due to

rework for offsite• Can test the market prices thoroughly• Client not prescribing the solution

Next steps

DfMA / Lean / Offsite

Supply chains rationalisedFlowlines in offsite facilitiesUse of semi skilled labourQuality improvementsReduction in trades on siteSafer site workingReduced lead time for facility deliveryLess CO2 in construction and operation

Digital Engineering

Project software providers not rationalisedInformation sharing protocols not rationalised

Without Digital Engineering improvements the DfMA capabilities cannot be achieved; holistically, routinely or consistently.Facility whole life value will not be realised.Capability is being created

X Capability is missing

ProposalHow can open sharable BIM Standards enable the universal adoption of DfMA & Lean construction?

IFCIndustry

Foundation Class