Technion paper sites customers as best QC protection
David Stiebel. . . .5/4/2010
A 2008 Technion School of Higher Education paper sites customers as the best defense for Quality Control in new home construction.
Proof of Quality Control issues comes from one of the leading education facilities in Israel. Read why customers seem to make the difference as the contractor’s quality control personnel fail in their duties...
Research Reports, 2008
Causes for Defects
in Residential Construction,
Identifying and Analyzing
Prof. Yehiel Rosenfeld Eng. Chanan Ben-Oz, M.Sc.
Costs apportioned to repairing building deficiencies
significantly affect the profitability of construction firms. Studies carried
out around the world have shown that costs incurred by building deficiencies
account for 10% to 15% of total project cost. In Israel's construction industry,
it is reasonable to assume that the situation is even worse, as attested to by
two major indications: the first is the report of the Center for Quality and
Excellence, which showed that the cost of non-quality accounts for 50% of the
output in Israel's construction industry (this finding should however be
discounted, as it includes overall costs); the second is the large number of
lawsuits filed in Israel regarding deficiencies in the quality of construction.
During 2005, over 3,000 lawsuits were filed across the country due to building
deficiencies in new dwelling units - constituting an 18% rise over 2004. Amid
the financial troubles that plague Israel's construction industry, this sector
also pays dearly for the repair of building deficiencies, which in many cases is
substantially greater than the project's net profit.
The purpose of this study was to identify and find out the
root causes of building deficiencies in the dominant and highly homogeneous
market segment of, high-density construction of new homes, which accounts for
70% of total residential construction in Israel, and nearly 50% of the total
output of the construction industry. Cutting down the waste of money in the
long-run requires thorough treatment of the root causes of this problem.
Identifying and eliminating the underlying causes would prevent building
deficiencies from being repeated in the future, whereas treating a particular
deficiency per-se would produce only minor, limited benefit. Our hypothesis was
that the root causes could be isolated, and classified into clearly
distinguishable primary groups.
The research method, as a whole, was to uncover the root
causes through a process of inference, which included the analysis of 100
individual case studies. We selected seven residential building firms, and
surveyed ten different sites of multi-storied new home construction.
The main research method was Root Cause Analysis,
employing a technique endorsed by the American Society for Quality. This method
comprises five stages, with the first three applying to each deficiency
separately throughout identification of its root causes, and the last two
applying to the total of root causes found.
The method's five stages are as follows: 1. Collection of
data pertaining to the deficiency and its causes, using the Quality Performance
Tracking System [QPTS], 1. Understanding the problem using a flow-chart that
also included costs at interim stages, at which tracking and repairing the
deficiency was possible, 2. Tracking down possible causes, and identifying the
root cause, using free-wheeling brainstorming, 3. Analysis of root causes -
using a statistical analysis and creating histograms and Pareto diagrams, 4.
Analysis of the causes for the statistical distribution using Cause and Effect
Although the declared purpose of the study was to identify
and analyze the root causes of construction deficiencies, a comprehensive
analysis of each one of the 100 deficiencies allowed for extracting additional
products with relevance to our subject.
The main products of this study are the following:
1. Typifying the deficiency (based on QPTS) including all
aspects of its makeup: classification, timing, specification of workers'
involvement and activity of the quality system, with the following principal
- Most deficiencies occurred during the framing stage of
work on the reinforced concrete frame (and walls) of the building, contrary
to the conventional wisdom in the construction industry that most building
deficiencies occur during the finishing phase.
- The finish phase is the apex of all quality activities:
it is indeed during this phase that most deficiencies were discovered, and
most activities affected by deficiencies appeared at this phase.
- 67% of all deficiencies discovered during the delivery
stage adversely affected the company's reputation.
- As a group, the frame and wall construction workers
caused the largest number of deficiencies (37%), and were found to be
performing insufficient control throughout the process.
- The developer's inspector identified only 3% of
deficiencies; inspectors' engineering skills and capabilities are not being
fully utilized for the good of the quality system.
- Tenants identified 20% of deficiencies, which means
that the quality system depends on the tenants acting as
- In 57% of cases the quality system's functioning
was found to be inadequate.
2. Identification and analysis of root causes showed that
these are distributed along primary classes, as follows:
- Work methods 45%
- Manpower 34%
- Management 19%
- Mechanized equipment 1%
- Raw Materials 1%
The final part of the study presents recommendations for
implementation. Some are tactical, referring to the construction site, and are
based on characterization of the deficiencies. These can be implemented by
project managers at low costs, without introducing extensive organizational
reforms. Other recommendations are strategic, referring to the construction
company and the building and construction industry at large. Based on analysis
of root causes, the latter, though demanding large-scale expenditures and
implementation of significant reorganization, are accompanied by strategic
Courtesy of Technion Institute: http://www.technion.ac.il/~nbri/research_reports/2007/550_2007_E.pdf
More info here: http://tx.technion.ac.il/~nbri/research_reports/