The effect of variations in management techniques on construction productivity

132 Pages·1992·4.4 MB·English

by  Wetherington, Leon E., 1939-

THE EFFECT OF VARIATIONS IN MANAGEMENT TECHNIQUES
ON CONSTRUCTION PRODUCTIVITY
By
LEON E. WETHERINGTON
A DISSERTATION PRESENTED TO THE GRADUATE SCHOOL
OF THE UNIVERSITY OF FLORIDA IN PARTIAL FULFILLMENT
OF THE REQUIREMENTS FOR THE DEGREE OF
DOCTOR OF PHILOSOPHY
UNIVERSITY OF FLORIDA
1992
UNIVERSITYOFFLORIDALIBRARIES
ACKNOWLEDGEMENTS
It is impossible to acknowledge all those who have
assisted in the completion of this project. I had the honor
and privilege of working with a very knowledgeable and
supportive committee whose members helped make this a
challenging and rewarding experience.
I am especially grateful to Dr. Weilin Chang, my
committee chair, whose supportive criticism and friendly
"pushing" kept me on the right track, and to Dr. Carlton
Coulter for providing insight into the structure of
research.
This research would not have been possible without the
cooperation of many individuals involved in the construction
industry in Florida whose ideas and comments have been
integrated into much of this study.
Finally I am grateful to my wife, Marilyn, whose
support throughout has been essential and willing provided.
ii
TABLE OF CONTENTS
ACKNOWLEDGEMENTS ii
LIST OF TABLES
ABSTRACT vi
CHAPTERS
I. INTRODUCTION 1
Purpose 2
Statement of the Problem 3
Hypothesis 7
Background 9
Scope 13
Plan of Research 14
Methodology 16
Organization of Dissertation 19
II. LITERATURE REVIEW 20
Introduction 20
EPrvooblluetmison of Productivity Improvement Efforts. . . 2312
Construction Scheduling 36
Management Functions 44
Summary 52
III. METHODOLOGY 54
Definition of Terms 55
Model Schedule 56
Discussion of Model Schedule Assumption 57
Research Model 59
IV. DATA ANALYSIS AND DISCUSSION 70
Data Analysis 70
Discussion 85
iii
V. CONCLUSIONS AND RECOMMENDATIONS 99
Conclusions 99
Recommendations 102
APPENDIX 107
REFERENCES 117
BIOGRAPHICAL SKETCH 121
iv
LIST OF TABLES
TABLE
1. PERCENT OF COSTS 67
2. MODEL SCHEDULE 68
3. MODEL SCHEDULE AND COSTS 69
4. BUILDER INFORMATION
From Part One 90
5. SUPERVISION
From Part One 91
6. FSrCoHmEDUPLarItNGOne 93
7. OBSERVED PROGRESS
From Part One 95
8. CFrOoMmPARPIarStONOnOeF CONSTRUCTION TIME 95
9. PAIRWISE COMPARISONS
From Part One 96
10. PAIRWISE COMPARISONS ADJUSTED FOR ADDITIONAL
INSPECTIONS
From Part One 96
11. PAIRWISE COMPARISONS OF JOB SITE FACTORS
From Part One 97
12. PAIRWISE COMPARISONS OF JOB SITE FACTORS
From Part Two 97
13. COMPARISONS OF TIME OF CONSTRUCTION BY GEOGRAPHICAL
AREA
From Part Two 98
14. COMPARISONS OF HOUSE SIZE BY GEOGRAPHICAL AREA
From Part Two 98
v
Abstract of Dissertation Presented to the Graduate School
of the University of Florida in Partial Fulfillment of the
Requirements for the Degree of Doctor of Philosophy
THE EFFECT OF VARIATIONS IN MANAGEMENT TECHNIQUES ON
CONSTRUCTION PRODUCTIVITY
By
Leon E. Wetherington
May, 1992
Chairman: Weilin Chang
Major Department: College of Architecture
Construction is one of the largest industries in the
United States, and productivity in construction is a key to
the growth in its economy. Measuring and identifying meth-
ods of increasing productivity are important roles of the
construction manager.
The purpose of this study was to identify the compo-
nents of management that have the most significant effect on
home building productivity and to integrate these components
into a paradigm to help guide the industry to increased
efficiency.
Productivity was defined as the value added to the
house for each day worked. A standardized scale was created
to compare the results of various builders' operations.
This scale was created by assigning a construction time and
vi
a value to each of 49 work activities of a typical Florida
single-family house.
Data were collected from each of six construction
projects over the duration of the construction process.
Data also were collected from 50 Florida home builders whose
annual production was at least 100 homes.
A qualitative and quantitative analysis of the data
from the construction projects demonstrated that produc-
tivity was higher in those projects where a formal schedule
was used. The schedule was either provided by management or
the superintendent was required to prepare one for each
house. Productivity was also higher for projects where an
on-site office and/or telephone was provided, and where
regular inspections were performed by someone other than the
project superintendent. Significantly lower productivity
was found where stringent building codes were enforced.
The builder interview data indicated that the most
common cause of delay was subcontractors not arriving at the
job site when scheduled. Both data sources indicated that
there was no significant difference in productivity when
multiple job sites were supervised by one superintendent.
However, the interview data revealed that productivity
decreased as the superintendent's travel distance between
jobs increased.
The results of this research present a clear statement
to builders that construction productivity is enhanced
vii
through formal scheduling and careful assignment of supervi-
sory responsibility. These results will also be useful to
educational institutions in developing professional continu-
ing education courses for constructors and superintendents.
viii
CHAPTER I
INTRODUCTION
Construction is one of largest and most important
industries in the United States. According to the U.S.
Bureau of Census (1990), construction accounts for up to 11
percent1 of the nation's gross national product (GNP), and
private residential construction accounts for approximately
4 percent of the GNP. Since the construction industry is so
important to the economy of the U.S., productivity in con-
struction is a source of concern not only for the construc-
tion industry, but to others as well.
In a study that included the industrial, commercial and
utility segments of the construction industry. The Business
Roundtable (1982a) concluded that effective planning and
scheduling systems can reduce construction time an average
of 10 percent and reduce the cost to the owner by 3 percent.
Many segments of the construction industry have adopted
various methods for improving productivity, such as the
planning and scheduling techniques used in large construc-
tion projects. However, in the home building industry,
traditional management methods still dominate, and no
1 Tables No. 691, 1250, and 1254 of the reference present
differing amounts for the value of construction. They show
$218.5, $525.9, and $397.7 billion respectively.
1
2
systematic study of the effect of variations in management
techniques has been conducted. It is expected that
effective planning and scheduling systems will reduce the
time required to construct single family homes even more
than the 10% predicted by The Business Roundtable for other
segments of the industry.
Purpose
The purpose of this study was to identify the compo-
nents of management that have the most significant effect on
home building productivity and to integrate these compo-
nents into a paradigm to help guide the industry to
increased efficiency. The purpose is not to improve produc-
tivity at the worker or crew level, but to improve the
overall productivity of builders' operations. The effects
of the following were investigated:
Scheduling
1. Formal Scheduling System.
A. Schedule prepared by management.
B. Schedule prepared by superintendent.
C. Schedule provided to sub-contractors.
D. Format of the schedule (CPM, Bar Chart, List of
Activities, etc.)
2. No Formal Scheduling System.
Supervision
1. Span of Control.
A. Percentage of the work done by subcontractors.