precast concrete building construction process …

PRECAST CONCRETE BUILDING CONSTRUCTION

PROCESS COMPARISON

Tian Xiaosheng, Graduate Student, Civil and Environmental Engineering Dept., University of Alberta, Canada, [email protected]

Farook Hamzeh, Associate Professor, Civil and Environmental Engineering Dept., University of Alberta, Canada, [email protected]

Agenda:

• Introduction

• Methodology

• Results

• Conclusions

2

• Previous research applied Lean

thinking to improve production to

solve the common problems.

（0311xue.com，2019）

Introduction

• Seldom research focuses on

comparing process status of PC

construction between developing

countries and developed countries.

3

Long lead times

Jumbled flow

Process waste

Methodology

Case study analysis

4

“How” and “Why” process differences occur in selected cases

Case selection Cases analysis using VSM Conclusion

Current state map

ComparisonFuture

state mapIdeal state

map

• Multifamily PC projects• Accessible information• Local typical implementation

methods

CURRENT STATE

MAPPING OF CASE 1.

Case 1

Location: Alberta, Canada

Project type: 6 story multifamily building

Precast concrete supplier (PS): Local large company

PS’s scope of work : design, produce, delivery, erection

Use 3D modeling in Design

5

Owner

Design 3D structure

drawingModify PC cells shop drawings

Produe PC cells Deliver PC cells Erect PC cells

Project Control

Owner

specification

Architecture

requirementStructure

requirementPCPI

InstructionPrecaster

requirement

Project

schedule

Precast Consultant

Production

plan

Contract

Order

Project

schedule

100%

0-1 days

30%

0-1 days

50%

0-1days

0%

5-10 days

70%

30 days

Standard product inventory CT= 40-80hrs/building

Resource =2 worker

CT= 95-270 hrs/ building

Resource = 2 worker

CT= 50-60 days/building

Resources =6-8 workers

CT= 30-40 days / building

Resource = two shift


Resouces = third party

transportation

1 to 2 weeks inventory

CURRENT STATE

MAPPING OF CASE 1.

Current problems:

• Extra shop drawing modification ranges from 5 minutes to 1.5 hours was needed to modify each drawing.

• The lead time between the production and delivery could be 1 to 2 weeks.

• The lead time before erection was one-month long, which was caused by the slow production rate and the fast erection rate

6

Owner

Design 3D structure



Project Control

Owner

specification

Architecture


requirementPCPI


requirement

Project

schedule

Precast Consultant

Production

plan

Contract

Order

Project

schedule

100%

0-1 days

30%

0-1 days

50%

0-1days

0%

5-10 days

70%

30 days

Standard product inventory CT= 40-80hrs/building

Resource =2 worker


Resource = 2 worker







transportation


CURRENT STATE

MAPPING OF CASE 2.

Case 2

Location: Beijing, China

Project type: 12 story multifamily building

Precast concrete supplier (PS): Local large company

PS is subcontractor

PS’s scope of work : design (2D drawings), produce, delivery

7

Contractor

Design 2D pc shop drawings

Modify PC cells shop drawings

Produe PC cells Deliver PC cells

Project Control

Owner

specification

Architecture


requirement

Precast

Design

standards

Precaster

requirement

Project

schedule

Production

plan

Subcontract Order

Project

schedule

Precast Engineering

house

2D

structure

drawings

Contractor s erection team

2D

structure

drawings

CT= 6-10

days/level

Resources

=12-18

workers

60%

10-30 days

90%

0-1 days

50%

0-1days

0%

10-15 days

CT= 400-800 hrs/building

Resource 4-8 worker


Resource = 1 worker





transportation


CURRENT STATE

MAPPING OF CASE 2.

Current problems:

• Long lead times before the start of shop drawings caused by the subcontract agreement.

• Long shop drawing design duration caused by traditional 2D-drawings.

• 2- 8 hrs. per drawing

• The complex connection method increased the erection duration.

8

Contractor

Design 2D pc shop drawings

Modify PC cells shop drawings


Project Control

Owner

specification

Architecture


requirement

Precast

Design

standards

Precaster

requirement

Project

schedule

Production

plan

Subcontract Order

Project

schedule

Precast Engineering

house

2D

structure

drawings


2D

structure

drawings

CT= 6-10

days/level

Resources

=12-18

workers

60%

10-30 days

90%

0-1 days

50%

0-1days

0%

10-15 days

CT= 400-800 hrs/building

Resource 4-8 worker


Resource = 1 worker





transportation


COMPARISON OF THE

CURRENT STATE PROCESSES

9

CaseCase 1 in Alberta,

CanadaCase 2 in Beijing,

ChinaBenefit

Involvement time Early late Better synergies, less error and rework

Components design More standardized Less standardized Shorter lead time, lower cost

Project participation Whole project cycle Limited project phases Better synergies and productivity

Engineering designThird party consultant

In-house engineering Better shop drawings quality

√

√

√

√

FUTURE STATE

MAPPING OF CASE 1.

Kaizens ( Improvement suggestions):

• Enhance the cooperation through an inhouse engineering department to improve quality of shop drawings

• Improve the shop drawing export function to reduce modification.

• Introduce a supermarket to

• Reduce the lead time (duration)

• Change the push system into a partial pull system

Owner

Design 3D structure



Project Control

Owner

specification

Architecture


requirementPCPI


requirement

Project

schedule

Precast Consultant

Production

plan

Contract

Order

Project

schedule

100%

0 days

80%

0-1 days

75%

0-1days

0%

5 days

90%

15days

Improved export

fucntion

Closer cooperation

CT= 40-80hrs/building

Resource =2 worker


Resource = 2 worker







transportation

Standard product inventory

10

FUTURE STATE

MAPPING OF CASE 2.

Kaizens ( Improvement suggestions):

• Apply BIM to improve the designefficiency.

• The precast supplier should positively participate in the project from early project phase to drive the design.

• Standardize the components design to improve efficiency and reduce cost.

Contractor

Design shop drawings


Project Control

Owner

specification

Architecture

requirement

Structure

requirement

Precast

Design

standards

Precaster

requirement

Production

plan

Subcontract

Order

Project schedule

Precast Engineering

house 3D structure

model

3D

structure

model

60%

5 days

90%

0-1 days

0%

3-5 days

Shared BIM

model

New informatic

tools


Standardize precast design Standard product

inventoryCT= 100-400 hrs/building

Resource 4-8 worker





transportation

Shared project

schedule

11

IDEAL STATE MAPPING FOR

FUTURE PROJECTS

Owner

Design 3D structure

drawing

Export and modify shop

drawing

Produe PC cells Erect PC cells

Project Control

Owner

specification

Architecture


requirementPCPI

Instruction

Precaster

requirement

BIM&Lean

Production

system

Precast Engineering

House

Contract

Order Project

Master

schedule

PLM with FRID tracking

MR enhanced

equipment

Project simulation


Resource =2 worker


Resource = 2 worker





ADCA/Autonomous

vehicle

Withdraw Kanban

Production Kanban

Industry 4.0

12


FUTURE PROJECTS

13

Owner

Design 3D structure

drawing


drawing


Project Control

Owner

specification

Architecture


requirementPCPI

Instruction

Precaster

requirement

BIM&Lean

Production

system

Precast Engineering

House

Contract

Order Project

Master

schedule


MR enhanced

equipment

Project simulation


Resource =2 worker


Resource = 2 worker





ADCA/Autonomous

vehicle

Withdraw Kanban

Production Kanban

• Kaizens( Improvement suggestions):• Combine BIM &

Lean to improve production system.

• Use data driven simulating to inform project duration and cost.

13


FUTURE PROJECTS

14

Owner

Design 3D structure

drawing


drawing


Project Control

Owner

specification

Architecture


requirementPCPI

Instruction

Precaster

requirement

BIM&Lean

Production

system

Precast Engineering

House

Contract

Order Project

Master

schedule


MR enhanced

equipment

Project simulation


Resource =2 worker


Resource = 2 worker





ADCA/Autonomous

vehicle

Withdraw Kanban

Production Kanban

• Kaizens :• Use RFID and other

sensors to collect data in the value chain for product lifecycle management.

14


FUTURE PROJECTS

15

Owner

Design 3D structure

drawing


drawing


Project Control

Owner

specification

Architecture


requirementPCPI

Instruction

Precaster

requirement

BIM&Lean

Production

system

Precast Engineering

House

Contract

Order Project

Master

schedule


MR enhanced

equipment

Project simulation


Resource =2 worker


Resource = 2 worker





ADCA/Autonomous

vehicle

Withdraw Kanban

Production Kanban

• Kaizens :• Use autonomous

vehicles to improve logistics

• An integrated system to utilize technologies in Industry 4.0 to improve the productivity

15


FUTURE PROJECTS

16

Owner

Design 3D structure

drawing


drawing


Project Control

Owner

specification

Architecture


requirementPCPI

Instruction

Precaster

requirement

BIM&Lean

Production

system

Precast Engineering

House

Contract

Order Project

Master

schedule


MR enhanced

equipment

Project simulation


Resource =2 worker


Resource = 2 worker





ADCA/Autonomous

vehicle

Withdraw Kanban

Production Kanban

• Kaizens :• Use virtual reality (VR) or

augmented reality (AR) to educate and assess the workers’ skills and improve safety

16


FUTURE PROJECTS

17

Owner

Design 3D structure

drawing


drawing


Project Control

Owner

specification

Architecture


requirementPCPI

Instruction

Precaster

requirement

BIM&Lean

Production

system

Precast Engineering

House

Contract

Order Project

Master

schedule


MR enhanced

equipment

Project simulation


Resource =2 worker


Resource = 2 worker





ADCA/Autonomous

vehicle

Withdraw Kanban

Production Kanban

• Kaizens :• Educate students with lean

construction concepts can reduce the knowledge barrier as lean experts are critical to the success of lean improvements for the precast supplier.

17

Conclusions

• Compared the current processes of the two selected precast construction projects in Canada and China, both have some places for future improvement.

• The project in Canada has less rework, shorter lead time and better productivity because of the earlier PS involvement, application of BIM and higher ratio of standardized precast design.

• The project in China has higher quality of shop drawings because of the in-house engineering capability.

• Enhanced cooperation and improved shop drawing export function are suggested to the Canadian PS to reduce the design duration and shorten the lead time, and applying BIM to design precast elements from the project early phase is the solution for the Chinese PS.

• A comprehensive future state map is proposed for future precast projects using a combination of new technologies in industry 4.0.

18

precast concrete building construction process …

Documents