1

Impacts to Labor Productivityin Steel Framing and the Installation and Finishing of Gypsum Wallboard

Steel framing and the installation and finishing of gypsum wallboard are a major component of every building project. Labor productivity is the largest single variable affecting of the framing and gypsum wallboard

contractors’ cost of performance. This study was undertaken to investigate ex-ternal impacts to labor productivity in this construction sector. The study mea-sured the impact of 38 variables on 226 separate projects. The study found that unexpected labor congestion, fragmentation, and overtime and added shift work negatively impacted labor productivity.

There have been a number of studies on labor productivity in the construction industry by major trade organizations such as the National Electrical Contrac-tors Association (NECA) and the Mechanical Contractors Association (MCA); academic institutions such as the Construction Industry Institute at University of Texas (CII); and government agencies like the US Army Corps of Engineers (USACOE) and the Department of Labor (L&I). These prior studies establish the baseline of literature in the labor productivity field and were used as the basis for deriving the productivity impact factors used in this study. This was the first such study to focus exclusively on steel framing and the installation and finishing of gypsum wallboard.

This study measured the productivity impact of thirty eight (38) separate vari-ables derived from the prior literature and an independent expert panel. These impact variables included: Extreme Weather, Trade Stacking, Crowding, Over-time, Added Shifts, Changes to the Work, Crew Over-Manning, Ramp-Up/Ramp-Down, Ripple Effects, and so on.

RESEARCH PROVIDED BYR. Brown Consulting Group LLC, Portland Oregon

AUTHORSGerald H. Williams, Ph. D., P.E. Construction Research, Inc.Timothy R. Anderson, Ph. D. Portland State University

PARTICIPATING ORGANIZATIONSNorthwest Wall and Ceiling Bureau (NWCB)

Northwest Wall and Ceiling Contractors Association (NWCCA)

Northern California Drywall Contractors Association (NCDCA)

Western Wall & Ceiling Contractors Association (WWCCA)

Associated Wall and Ceiling Contractors of Oregon and Southwest Washington (AWCC)

©2009 Copyright Northwest Wall and Ceiling Bureau. Reproduction, copying and unauthorized use strictly forbidden.

SUMMARYFull length copies of this study may be purchased through the Northwest Wall and Ceiling Bureau.

www.nwcb.org

2

The major finding of this study was that all of the major impact variables negatively correlated with labor productivity (meaning the more severe the impact, as recorded on a scale of one to five, the greater the impact to labor productivity). From the Framing Analyses, 28 of the 38 variables were statistically significant at the 99th percentile.

The second major finding was that there was a high degree of correlation between certain sets of variables, which were ultimately broken into three groups: Causes,

Impact Effects, and Direct Impacts. Causes were variables like, Quality of the Plans and Changes in the Work, which resulted in Impact Effects like Crowding, Trade Stacking, Ramp-Ups/Ramp-Downs and Remobilizations. The Impact Effects fall into two general categories: Congestion related and Fragmentation related variables. Direct Impacts are essentially environmental factors, such as Extreme Weather, Night Shifts, Overtime, and so on, which affect labor productivity irrespective of other physical changes in the way the work must be performed.

Calculating Impacts

The following worksheet allows you to calculate the level of impact on this project.

What was the impact of:(Circle on value in each row)

None Severe Sum ofScores

Divideby 3=

0 1 2 3 4

Fragmentation Out of sequence work 0 1 2 3 4

Remobilizations and go-backs 0 1 2 3 4

Ramp-ups/ramp downs of labor forces 0 1 2 3 4

Congestion Trade stacking (labor congestion due to other trades) 0 1 2 3 4

Labor congestion of your own crews 0 1 2 3 4

Trade stacking (labor congestion due to other trades) 0 1 2 3 4

Ranges of Impact

The following table presents the levels of impact for the various trades, based on a 95% confidence interval:

Upper Range of typically observed productivity impacts on:

Framing Hanging Finishing

Impact observed on mean: Congestion 44% 40% 47%

Fragmentation 50% 41% 47%

Acceleration 42% 42% 47%

©2009 Copyright Northwest Wall and Ceiling Bureau. Reproduction, copying and unauthorized use strictly forbidden.

SUMMARY: IMPACTS TO LABOR PRODUCTIVITY IN STEEL FRAMING AND THE INSTALLATION AND FINISHING OF GYPSUM WALLBOARD

3

Congestion and FragmentationBoth Congestion and Fragmentation are in essence asking the contractor to perform the work under conditions that were not as originally planned.

In the congestion mode, the contractor is forced to per-form the work in a more crowded manner than anticipated. Framing and gypsum wallboard contractors typically want, like most contractors, a free hand in executing their work. In the ideal world, the construction project would be vacated entirely to allow the framer free reign to build his walls without the interference of other trades. But, in the practical world that is not possible. But, while a modicum

of trade interference is expected, serious trade stacking and crowding of forces required to accelerate the work or work in a congested environment is not.

Likewise, work fragmentation, a condition that exists solely because the general contractor or owner fails to release an appropriate or economical amount of work for the fram-ing or gypsum wallboard contractor to execute, can greatly impact labor productivity. Finally, based on this study, these impacts to the cost of production appear to be more pro-nounced in steel framing and the installation and finishing of gypsum wallboard than in the other trades previously studied and documented in the literature.

©2009 Copyright Northwest Wall and Ceiling Bureau. Reproduction, copying and unauthorized use strictly forbidden.

SUMMARY: IMPACTS TO LABOR PRODUCTIVITY IN STEEL FRAMING AND THE INSTALLATION AND FINISHING OF GYPSUM WALLBOARD

0

4

0 1 2 3 4Mean Fragmentation

Mea

n C

onge

stio

n

Projects in this region are statisticlally likely to have productivity losses exceeding 10% as a function of fragmentation and congestion

Projects in thisregion arestatistically

likely to have productivity

losses from these causes

Projectsin this region arestatistically unlikely to haveproductivity losses from these causes

0

100

200

300

400

500

600

700

800

0

100

200

300

400

500

600

700

800

06/0

7/04

06/2

1/04

07/0

5/04

07/1

9/04

08/0

2/04

08/1

6/04

08/3

0/04

09/1

3/04

09/2

7/04

10/1

1/04

10/2

5/04

11/0

8/04

11/2

2/04

12/0

6/04

12/2

0/04

01/0

3/05

01/1

7/05

01/3

1/05

02/1

4/05

02/2

8/05

03/1

4/05

03/2

8/05

04/1

1/05

04/2

5/05

05/0

9/05

05/2

3/05

06/0

6/05

06/2

0/05

07/0

4/05

07/1

8/05

08/0

1/05

08/1

5/05

08/2

9/05

09/1

2/05

09/2

6/05

10/1

0/05

10/2

4/05

11/0

7/05

11/2

1/05

12/0

5/05

12/1

9/05

01/0

2/06

01/1

6/06

01/3

0/06

02/1

3/06

02/2

7/06

03/1

3/06

03/2

7/06

04/1

0/06

Tota

l Man

days

Wee

kly

Week Beginning

Baseline Schedule 3OCT05 P3 Schedule

Max Crew Size 200 Man days per

week

Estimated productivity loss of 498 to 575 man days during

this period based on 3OCT05 schedule update

Figure 1: Illustration of Acceleration resulting in Congestion on the project

Taken from an actual project, this figure illustrates impending labor congestion due to acceleration of the work in order to maintain the project schedule.

The figure below, from the same project, shows the actual performance on the job, which was greatly fragmented compared to the plan (in both cases, the planned work is shown in Green.)

4

©2009 Copyright Northwest Wall and Ceiling Bureau. Reproduction, copying and unauthorized use strictly forbidden. Cover Photo © Jánis Miglavs. www.jmiglavs.com

Full-length copies of this study may be purchased through the Northwest Wall and Ceiling Bureau.1032-A NE 65th, Seattle, WA 98115 • Phone (800) 524-4215 • info@nwcb.org • www.nwcb.org

NCDCA

ASSOCIATED WALL & CEILING CONTRACTORSof Oregon and S.W. Washington, Inc.

0

100

200

300

400

50012

/1…

1/15

/04

2/12

/04

3/11

/04

4/8/

04

5/6/

04

6/3/

04

7/1/

04

7/29

/04

8/26

/04

9/16

/04

10/1

…

11/1

…

12/9

/04

1/6/

05

2/3/

05

3/3/

05

3/31

/05

4/28

/05

5/26

/05

6/23

/05

7/21

/05

8/18

/05

9/15

/05

10/1

…

11/1

…

12/8

/05

1/5/

06

2/2/

06

3/2/

06

3/30

/06

4/27

/06

5/25

/06

6/22

/06

7/20

/06

8/17

/06

9/14

/06

Tower - Basement (Framing)

0

100

200

300

400

500

12/1

…

1/15

/04

2/12

/04

3/11

/04

4/8/

04

5/6/

04

6/3/

04

7/1/

04

7/29

/04

8/26

/04

9/16

/04

10/1

…

11/1

…

12/9

/04

1/6/

05

2/3/

05

3/3/

05

3/31

/05

4/28

/05

5/26

/05

6/23

/05

7/21

/05

8/18

/05

9/15

/05

10/1

…

11/1

…

12/8

/05

1/5/

06

2/2/

06

3/2/

06

3/30

/06

4/27

/06

5/25

/06

6/22

/06

7/20

/06

8/17

/06

9/14

/06

Tower - 1st Floort (Framing)

0

100

200

300

400

500

12/1

…

1/15

/04

2/12

/04

3/11

/04

4/8/

04

5/6/

04

6/3/

04

7/1/

04

7/29

/04

8/26

/04

9/16

/04

10/1

…

11/1

…

12/9

/04

1/6/

05

2/3/

05

3/3/

05

3/31

/05

4/28

/05

5/26

/05

6/23

/05

7/21

/05

8/18

/05

9/15

/05

10/1

…

11/1

…

12/8

/05

1/5/

06

2/2/

06

3/2/

06

3/30

/06

4/27

/06

5/25

/06

6/22

/06

7/20

/06

8/17

/06

9/14

/06

Tower - 2nd Floort (Framing)

Figure 2 Illustration of Work Fragmentation

In the figures above, the contractor intended to mobilize to a location two times for corridor and partition walls. As it turned out, he was forced to mobilize and demobilize nearly 20 times at each location. Labor productivity was reduced to more than 30 percent below the estimate.

SUMMARY: IMPACTS TO LABOR PRODUCTIVITY IN STEEL FRAMING AND THE INSTALLATION AND FINISHING OF GYPSUM WALLBOARD