טכניון מכון טכנולוגי לישראל
הטכניון מכון טכנולוגי לישראל - בית הספר ללימודי מוסמכים  
M.Sc Thesis
M.Sc StudentBen Oz Chanan
SubjectIdentification and Analysis of Root Causes for Construction
Defects
DepartmentDepartment of Civil and Environmental Engineering
Supervisor Professor Yehiel Rosenfeld


Abstract

Costs apportioned to repairing building deficiencies account for 10% to 15% of total project cost and significantly affect the profitability of construction firms. The purpose of this study was to identify the root causes of building deficiencies . Our hypothesis was that the root causes could be isolated, and classified into clearly distinguished primary groups.

The main research method was Root Cause Analysis, employing a technique endorsed by the American Society for Quality. 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],
  2. Understanding the problem using a flow-chart that also included costs at interim stages, at which tracking and repairing the deficiency was possible,
  3. Tracking down possible causes, and identifying the root cause, using free-wheeling brain-storming,
  4. Analysis of root causes - using statistical analyses and creating histograms and Pareto diagrams,
  5. Analysis of the causes for the statistical distribution using Cause and Effect analysis.

The three 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 .
    2. A near exponential regression curve discovered that any delay in identifying deficiencies and repairing them results in soaring costs.
    3. Root causes are distributed along primary classes, as follows:

§         Work methods 45%

§         Manpower 34%

§         Management 19%

§         Mechanized equipment 1%

§         Raw Materials 1%

recommendations for implementation includes tactical ones, referring to the construction site, and strategic ones, referring to th construction industry at large.