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Factors Affecting Design and Documentation Quality in Construction
Industry
BY: MOSTAFA ISMAIL DARWISH
CEM 520: Construction Contracting and Administration03 June 2007
Presented BY:Osama Mohsen
Ibrahim AlRamadanMuidh AlGahtani
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Presentation Outline
Introduction
Objectives and Scope
Literature Review
Research Methodology
Data Analysis Approach
Finding and Results
Conclusion and Recommendations
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Introduction To allow construction contractors to transform the design
concepts and ideas into physical product, the designers provide drawings the specifications. The quality of these design documents greatly affects the efficiency of the construction phase.
To determine the level of documentation quality, a number of attributes should be considered such as time, accuracy, completeness, coordination and conformance.
Any improvement in design and documentation quality will lead to improvements in the construction process.
The awareness of the value of quality design and documentation would ensure that sufficient time and fees are available to allow designers to provide the needed level of services. In addition, more projects will be completed on time, within budget, and with less rework and disputes.
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Objectives and Scope
Objectives of the Study To identify main factors affecting design and documentation
quality in the Saudi Arabia construction industry To investigate the nature and extent of the impacts of design
and documentation deficiencies on project cost and time To calculate the percentage agreement between different
project participants on the ranking of the factors
Scope and Limitations Experts with more than 10 years experience in projects greater
than SR 10 million All building projects built in the Eastern Province of Saudi
Arabia The focus is on traditional procurement projects in the Public
sector
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Literature Review
Terminology
“Quality” is defined as meeting the requirements of the owner, design professional, and constructor as specified by contract, while complying with laws, codes, standards, regulatory rules, and other matters of public policy
“Quality Design” is the design that is effective and compatible with the best possible economy and safety
A related term to design quality is “Deviation”. which is defined as a departure from established requirements and may be classified as an imperfection, nonconformance, or defect based on its severity
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Literature Review
Design and Documentation Attributes
On a previous study, conducted by Tilley and McFallan in 2000, a list of attributes has been identified as having a direct impact on the quality of design and documentation
Design Quality Attributes (out of 22) Functionality Relevancy Competence and Experience
Documentation Quality Attributes (out of 12) Accuracy Clarity Final checking
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Literature Review
Design Deficiencies
Most design deficiencies can be categorized as one of the following three types:
Contract document conflicts Interdisciplinary coordination errors Technical compliance discrepancies
The three major causes of contract modifications are: Design deficiencies User requested changes Unknown site conditions
According to previous studies, about 56% of all contract modifications are needed to correct design deficiencies
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Literature Review Improving Design and Documentation Quality
In order to improve the overall quality of design and documentation, the following issues need to be considered:
The procedure for selecting a consultant or designer, and the basis for payment of fees
The method of selection of a contractor has shortcomings
There need to be communication with the contractor at an early stage of the design
The lack of formal techniques and procedures for managing the design process
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Literature Review
Factors from Previous Studies
One study, performed by Tilley and McFallan (2000) in Australia, lists 23 factors. Most important factors are:
unrealistic expectations by clients in terms of fees, service and timing
low fee structures insufficient profits to enable the training of staff
Another study, conducted by Andy and Minato (2003) in Japan, lists 26 factors. Most important factors are
insufficient design time client’s tendency to shop around for design fee low design fee
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Research Methodology
Research Process
The research methodology can be summarized in 5 steps:
Step1: Literature review in order to identify the important factors
Step2: Questionnaire development information on the respondents and Importance of the factors
Step3: Field Survey
Step4: Statistical Analysis of the data
Step5: Major finding and results
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Research Methodology
Questionnaire Design
After reviewing the literature, the most influential factors were determined
An initial questionnaire with (43) factors was developed
A pilot study, then, with (6) construction experts was done ( analysis the factors)
Finally, a new version of the questionnaire with (39) factors was developed and surveyed
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Research Methodology
Respondents Restrictions
Four (4) restrictions were imposed on the selection process of the respondents as follows:
Contractor with Grade-2 or better (Chamber of Commerce)
Building Projects Large projects (10 millions SR or more) Eastern Province of KSA
According to the Chamber of Commerce: 72 Consultants 131 Contractors 88 Ownerwill satisfy the four (4) restrictions mentioned above
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Data Analysis Approach
Sample Size
Sample size were determined using statistical principles of exploratory research as follows:
n0 = (p*q) / V² n = n0 / [ 1+ (n0/N)]
where:n0: First estimate of sample size.p : The proportion of the characteristics being
measured in the target population.q : Complement pf 'p' or 1-p.V : The maximum standard error allowed.N : The population size.n : the sample size
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Data Analysis Approach
Sample Size
To maximize n: p is set to 0.5 To account for error in qualitative answers: V is set to
10% or 0.1
Using these values, the sample size is found to be: Contractors ( N= 131) , n= 21 Consultants (N= 72) , n=19 Owner (N= 88) , n= 13
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Data Analysis Approach Important Index ( II )
The questionnaire is designed to have (39) factors and each has five options with the following scale (interval):
“Always”= 100% “Often”= 75% “Occasionally”= 50% “Rarely”= 25% “Not at all” = 0%
The Important Index (II) is calculated as follows:II = 100X1 + 75X2 + 50X3 + 25X4 + 0X5
(X1+X2+X3+X4+X5)where :
X1 : number of respondents answering “ Always”X2, X3, X4, X5 is the same for the rest
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Finding and Results General Information of the Respondents
The respondents participated in the questionnaire have the following characteristics:
Almost 80% are over 15 years of experience
57% of the Contractors are Grade-1 and the rest are Grade-2
94% of the Consultants are medium size (between 100 and 400 employees)
48% of the Contractors are large size (more than 400 employees)
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Finding and Results Ranking by the Important Index
By applying the important index formula, the most important factors that affecting design and documentation quality was determined. The most five important are the following:
Last minute changes by client
Insufficient overall design time
Unstable client's requirements
Waiting for client decision
Consultants tends to copy & modify from their previous work to minimize time and cost
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Based on the responses of the survey, it is concluded that the reduction in the level of design fees together with limited time available to develop the design work and in addition to, instability of the owner requirements and decisions throughout the design process have caused problems in the design and documentation quality.
The responses from almost all contractors (94%) indicated that the standard of design and documentation has an influence on the price submitted.
(88%) of respondents stated that the quality of design and documentation influenced the time required to complete the project.
Conclusion
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The responses indicated that poor quality design documentation was costing owners and developers an average of 9% on the estimated project cost and a similar amount in time for the project duration.
They indicated that other issues were due to design and documentation deficiency, just fewer than 40% of the time.
Percentage agreement of 44.3% was observed between consultants and contractors groups on the ranking factors.
Percentage agreement of 41.9% was noted between owners and contractors groups on the ranking of factors.
Percentage agreement of 3.5% was found between owners and consultants groups on the ranking of factors.
Conclusion
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The Kendall’s rank correlation, T=0.53, which indicates moderate agreement in the ranking of the factors by overall construction groups.
The rank agreement calculations show that there is a moderate agreement correlation among designers in Saudi Arabia, Australia, and Japan on the ranking of the main factors affecting design and documentation quality.
Conclusion
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The results of the survey show a need of developers to allocate funds and time to the planning and design phases of a project , in order to maximize construction process efficiency and minimizes overall project costs and duration.
Improvements in construction process efficiency will result from creating an awareness of the value of quality design and documentation and implementation of selection criteria that includes consideration of the designer’s skills experience.
Consultants (designers) need to consider properly the role and proper contribution of the owners and contractor when preparing project documentation , to ensure that it meets their requirements and objectives in relation to their contract obligations.
Recommendations
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Owner and contractor proper involvement in the early stage of the design process will be effective in improving overall design documentation quality.
The need for owners and developers to allocate adequate funds and time to the planning and design phases of a project in addition to stable decision and specific requirements, in order to maximize construction process efficiency and minimize overall project costs and time (duration).
Recommendations
23
Very useful study since it address real problems encountered in construction industry.
The number of factors is large, 39. Some factors can be combined together.
What is the source of these factors? It is not mentioned whether or not the author create some of the factors use them from previous studies.
Repeated information in literature review with no coherent between some sections.
The study does not suggest procedural solutions that can be followed by the concerned parties.
Critique
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Thank You
Questions!