Hyun Woo “Chris” Lee, PhD School of Civil and Construction

Engineering Oregon State University

EXPLORING OPPORTUNITIES FOR APPLYING LEAN CONSTRUCTION TO ELECTRICAL PREFABRICATION

ELECTRI Council Meeting San Diego

January 23, 2015

Research Report • Funded by ELECTRI

through the Early Career Award in 2013

• For more details, refer to http://apps.necanet.org/store/products/index.cfm/f3406

Hypotheses 1. Electrical construction has

its own unique barriers to prefabrication

2. A project that applies more lean principles provides more opportunities for electrical prefabrication

Photo courtesy of Oregon Electric Group

Study Objectives and Steps

Identify unique barriers to electrical prefabrication

Investigate a list of lean principles

Develop a leanness scoring matrix

Increased Chances for Electrical Prefabrication

1

2

3

Interviews with 18

experts in OR, WA, CA

Literature review

4 case studies with 3 EC’s

Hypothesis testing

Cross case analysis

Benefits of Electrical Prefabrication

Controlled Environment

Shift from Job Site to Offsite

Shop

• Increased productivity • Increased quality • Increased safety

o Increased labor reliability o Reduced workers fatigue o Reduced job congestion o Less storage space o Increased recycling

Intr

insi

c •Lack of culture for early involvement and pre-planning

•Lack of large equip

•Lack of BIM capacity

Extr

insi

c •Small-sized materials

•Lack of repetition

•Elect trade not invited to pre-planning

•Lack of design quality

Unique Barriers to Electrical Prefabrication — Compared to Mechanical

Lean Principles Definitions

1) Organize Cross-Functional Teams A group of people working together and applying their different functional expertise to the job they are collectively working on.

2) Pursue a Set-Based Strategy Development of multiple alternatives and choosing from them at the last responsible moment.

3) Use the Reliability Based Scheduling Schedules with more details should be done near the execution time when more reliable information is available.

4) Use Just-In-Time (JIT) Delivery To produce the necessary units in the necessary quantities at the necessary time.

5) Use Fail-Safe for Quality Control To eliminate product defects by preventing, correcting, or drawing attention to human errors as they occur (Poka-Yoke)

6) Lay out the Workshop According to Five S’s Five S’s refer to sort, straighten, standardize, shine, and sustain, which are methods used for managing and organizing workshop.

7) Standardize the Process The elements of work process should be kept consistent, such as the labor load, work methods, and materials.

8) Identify Waste in the Process To Identify non-value-added tasks and eliminate them.

8 Lean Principles for Elec Prefab

CASE 1 – Hanger Cable for Lighting Fixtures

Conventional Process

Prefab Process

CASE 2 – Conduit Bending without BIM

Conventional Process

Prefab Process

1

1

• Suppliers have materials stored at the prefab shop

• Required materials will be pulled from the rack when needed.

• An application, called iSAM, on smartphone/tablet is used to scan the bar code of materials, and they will be automatically invoiced.

Case 2 – Just-In-Time Delivery

CASE 3 – Conduit Bending with BIM

Prefab Process With BIM

Isometric (ISO) drawings easily produced by using BIM

CASE 4 – Electrical Box Assemblies Conventional Process

Prefab Process

Case 1 Case 2 Case 3 Case 4 Organize Cross-Functional Teams 3 3 4 2 Pursue a Set Based Strategy 0 3 3.5 0 Use Reliability Based Scheduling 3 4 4 4 Use Just-in-time (JIT) Delivery 3 5 5 3 Use Fail-Safe for Quality Control 1 3 3 3 Lay Out the Workshop According to 5S’s

3 4 4 3 Standardize the Process 2 4 4.5 3 Identify Waste in Process 2 4 4 2

“Leaness” Scoring Matrix for Cross-Case Analysis

Case 3

Case 2

Case 4

Case 1

Level of Prefab Sophistication

Testing Hypothesis 2

• Electrical prefabrication can lead to significant benefits.

• Electrical construction faces an unique set of barriers to prefabrication (Hypothesis 1).

• 8 lean principles were identified to help overcome the barriers.

• The cross-case analysis shows that projects with more lean principles provide more chances for electrical prefabrication (Hypothesis 2).

Conclusion

Hyun Woo “Chris” Lee, Ph.D. Assistant Professor School of Civil and Construction Engineering Oregon State University 541.737.8539 HW.Chris.Lee@oregonstate.edu

Thanks! Questions?