Emmanuel Chidiebere Eze
Federal University of Technology Minna, Nigeria
E-mail: emmanueleze001@gmail.com
John Ebhohimen Idiake
Federal University of Technology Minna, Nigeria
E-mail: idiakeje@futminna.edu.ng
Bashir Olanrewaju Ganiyu
Federal University of Technology Minna, Nigeria
E-mail: bashiroganiyu@futminna.edu.ng
Submission: 07/09/2017
Accept: 06/03/2018
ABSTRACT
Rework
is systemic and a recurring decimal, and it is triggered by several factors
whose emergence create scenarios that degrades project cost, quality and
schedule performance, and overall project performance. This study therefore
examined the perception of construction professionals on the factors that
triggers the emergence of rework in the Nigerian construction industry. This
was achieved by determining the predominant rework triggers that affect project
performance, identifying rework triggers in which the professionals view varies
significantly, and examining the category of rework risks triggers that
contribute more to rework incidences. The study adopted a quantitative survey
approach in which structured questionnaire was adopted as the research
instrument. Mean item score was used in ranking the professionals perception on
rework triggers, and Kruskal-Wallis H test was used to identify the variables
in which the professionals view varies. The study concluded that:
contractor-related and design-related causes are the major categories of rework
risks triggers. Unclear instruction to workers, Shortage of skilled
supervisors, incomplete and inaccurate information are the predominant triggers
of rework. The professionals view varies significantly on nine factors which
cut across the four categories of rework triggers. It was recommended that
there is need for clarity, effectiveness and timeliness of instruction and
information dissemination among project participants, and the use of skilled
and experienced professionals, skilled supervisors and proper implementation of
quality management practices by both the design consultant and contractor
throughout the project’s phases.
Keywords: Built
environment professionals, Construction Industry, Nigeria, Rework, Risks
triggers
1. INTRODUCTION
The
construction industry is the driving force behind socio-economic development of
any nation (SAIDU; SHAKANTU, 2016a). The industry is the means through which
countries upgrade their national economies (ANIL; DANIELRAJ, 2016).
Construction industry takes huge amount of money, time and energy (MESHKSAR,
2012). It is among the major industries that contribute to economic growth and
civilization; as such, its importance is approved in all communities (MESHKSAR,
2012). The activities of the industry improves the quality of life by providing
infrastructures such as buildings, roads, hospital, schools among other
facilities (SAIDU; SHAKANTU, 2016c ).
In
spite of the significance of the construction industry, it is faced with the
problems of poor financial performance, high cost of project delivery, poor
quality and material waste, and failure to deliver value to clients on schedule
(ABDUL-RAHMAN et al., 2013; SAIDU; SHAKANTU, 2016c; ANIL; DANIELRAJ,
2016). Consequently, the industry has
been extensively criticized for poor performance and ineffective productivity
(SIMPEH, 2012). The cost and schedule overruns often experienced in the
construction projects delivery is directly and significantly attributable to
rework factors (HWANG et al., 2009; ANIL; DANIELRAJ, 2016).
Rework
is one of the major factors responsible for the setback experienced in the
industry (SIMPEH, 2012; ANIL; DANIELRAJ, 2016). Rework is the main contributor
to time wastage and schedule overruns which ultimately impact on cost,
resources and quality (LOVE; EDWARDS, 2004a; ANIL; DANIELRAJ, 2016). Love
(2002a) opined that rework would naturally increase total project costs by
12.6%. Similarly, Davis et al (1989) reported that rework could cause
additional cost to construction of up to 12.4% of the total project cost.
Enshassi
et al. (2017) carried out a studied which was aimed at identifying the factors
that contribute to Rework and their Impact on Construction Projects Performance
in Palestine. The study examined the views of contractors, consultants and
project owners using questionnaire survey, and concluded that contractor’s
related rework causes and human related rework causes are the major categories
which impact on project performance.
Mahamid
(2016) analysed the cost and causes of rework in residential building projects
in West Bank, Palestine. The study adopted questionnaire survey among 78
contractors. The study revealed that construction projects are mostly affected
by client and contractors related factors.
Ajayi
and Oyeyipo (2015) studied the effect of rework on project performance in
building project in Lagos State, Nigeria. The study adopted questionnaire
survey with 52 construction professionals, and found out that rework impact on
project cost and project schedule. The most ranked causes of rework under
client related, design related, and subcontractor related causes were Poor
communication with design consultant, Use of poor quality materials, poor
workmanship, lack of experience and knowledge of design and construction
process, and incomplete design as at time of design.
Anil
and Danielraj (2016) carried out a study whose aim was to determine the
underlying causes of rework during construction, and their impact on the
overall project performance in order to develop effective prevention strategies
in India construction industry. The study adopted a questionnaire survey among
professionals, and found out that poor communication between design consultants
and clients, deviation from drawings, poor coordination of resources, setting out
errors , and low-skilled labour employed by subcontractors are the major causes
of rework and these cut across the activities of the client, consultants, and
contractors.
It
is vital to know that these studies did not compare the responses of the professional
regarding the factors that triggers the occurrence of rework. It is based on
this, that this study assessed the relationship that exists among construction
professionals view regarding the factors that triggers the occurrence of
rework. The aim of this study is to examine the perception of construction
professionals on the factors that triggers the emergence of rework in the
Nigerian construction industry, with a view to ascertaining factors where their
views differs significantly.
The
specific objectives of this study are; to determine the predominant rework
triggers that affect project performance, to identify rework triggers in which
the professionals view varies significantly, and to examine the category of
rework risks triggers that contribute more to rework incidences. The hypothesis
that guided this study is H1: there is no significant difference in
the perception of the different professions regarding the rework risks
triggers.
Constructions
professionals do recognize that rework have considerably impact on project
performance (LOVE; EDWARDS, 2004a). Improved quality requires an
understanding of the root causes of the rework (LOVE et al., 1999a). Rework is a
major problem that has befallen the construction industry of Nigeria and better
understanding of the factors that trigger their emergence will assist the
project managers and other participants to ascertain the most effective
techniques to improve or eliminate rework.
2. LITERATURE REVIEW
2.1.
Rework
Risk Trigger
An event or condition that causes a
risk to occur is known as risk trigger. Risks are the potential for something
usually negative to happen (SPACEY, 2016). According to Spacey (2016), a
trigger is root cause of an event. Based on this definition, Rework risks
triggers are factors that can cause rework to emerge in construction work, and
this could happen throughout the phases of construction projects. These
triggers are causes, factors, variables, events, or occurrences that could
result to rework.
Rework occurs when a product or service
does not meet the requirements of the customer (LOVE et al., 1999a). As a
result, the product is distorted in accordance with the requirements of the
customers. The production of substandard
products or poorly performs services by organisation participating in a project
is not intentional; however, errors are accepted as part of human nature
(SIMPEH, 2012).
Enshassi et al. (2017) categorized
fifty-seven rework factors into Construction process related causes, Materials
and equipment supply related causes, Client related causes, Contractor related
causes, Human resource capability related causes, Design related causes, and
External environment related causes. The
study carried out by Enshassi et al. (2017) revealed that contractor and human resources capacity
related factors are the major factors that trigger rework and they have the highest impact on construction projects
performance. The root causes of construction rework are categorised into
client-related, design-related, and Contractor-related factors (LOVE; EDWARDS,
2004a).
Client
factors identified by Palaneeswaran (2006) include: poorly prepared contract
documentation; Poor communication with design consultants; inadequate briefing;
Lack of client involvement in the project; Lack of funding for site
investigation; the inexperience and lack of knowledge of the design and
construction processes. Inadequate
briefing, Lack
of knowledge of construction
process, Lack of funding allocated for site
investigation are they principal causes of rework that
impact on project performance that are related to the project owner (ENSHASSI
et al., 2017).
According to Dalty and Crawshaw
(1973) poor flow of communication or deficits in the flow of communication
among members of the client and design team results in omission and errors
being incorporated in contract documentation unnoticed. As such the clients and
their project team members must ensure that they communicate and work together
amicably; for the projects to be delivered on times or ahead of schedule (WALKER,
1994).
According to Simpeh (2012) lack of
coordination and integration of design by the design team have resulted to deficiencies
in design; and these have contributed greatly to the causes of rework.
Josephson and Hammarlund (1999) supported this view by pointing out that
communication problems is primarily the source of design-related rework in
construction. In the same vein, Austin et
al. (1994) asserts that poor use of
information technology in communicating and managing project information worsens
the volume of rework occurring in construction projects.
According
to the results of Love and Li (2000), the poorly coordinated and integrated
members of the design team delay the exchange of information between them. Design errors and Omission, Incomplete
information for design, incomplete design and lack of professionalism
are the major causes of design related rework (ENSHASSI et al., 2017).
According to Love et al. (2010), the argument therefore,
is that design professionals lack the professionalism due to design fee
reduction which has further resulted in production of contract documents that
are incomplete and inadequate. This according to Simpeh (2012) leads to rework
and may lead to dispute and smear the image of participants in the long run.
The failure to plan work by most
supervisors, adequately direct activities and communicate with workers has
impact on increasing the volume and costs of rework (SIMPEH, 2012). Enshassi et
al. (2017) revealed that attempt to fraud, Competitive
pressure / low contract value, Unqualified technically,
and Poor quality system
as the major contractors related rework causes. The efficiency of the major
contractor’s construction planning efforts has effect on the success of the
projects of the Site management team and subcontractors (FANIRAN et al., 1999; IRELAND, 1985; SIMPEH,
2012; WALKER, 1994).
Project without a quality management
system in place essentially increases the cost of project by 10% due to rework
(CUSACK, 1992). Inability to safeguard (or protect) works which implies failure
during alteration works to protect certain parts of a building (BARBER et al., 2000; SIMPEH, 2012). Setting-out
errors, Poor workmanship, multi-tasking
and time pressure (LOVE et al.,
1999a; SIMPEH, 2012; JOSEPHSON; HAMMARLUND, 1999).
For the subcontractors, specific
rework factors found by: Love and Smith
(2003), Love et al. (1999a) ,
Josephson et al. (2002), Oyewobi and
Ogunsemi (2010); and Rounce (1998) are
damage to other trade work due to carelessness, inadequate supervision, poor
choice of materials, poor managerial skills, and low skill level of
construction artisans and labour. Poor skill levels of; the client's project
manager, the design team and subcontractors (LOVE et al., 2002).
Smallwood (2000) confirmed that
clients perceived that late information, poor management of the design
activities, poor planning, lack of concern for the environment, low skills
level among the workers, and overall poor management were the causes of poor
contractor performance. According to Wasfy (2010), the factors that lead to the
rework of material and equipment supplies include non-compliance with
specifications, untimely deliveries, prefabrication not to project
specifications, and unavailability of materials at right time and place when
needed.
Environmental factors that causes
rework are Political situation (Siege- conflicts), Economy (Inflation, exchange
rates, market), and Physical condition (ENSHASSI et al., 2017). Mahamid (2016)
reported that weather and lack of safety are the major environmental causes of
rework that affect project performance. The construction environments are
confronted with problems related to production, design changes, general quality
of materials and quality of work and use of available capacity (MAHAMID, 2016).
Majority of construction projects
are faced with a lot of causes that leads to rework, such as; omissions,
alteration, failures, proper communication, and inadequate coordination and
collaboration between stakeholders (ANIL; DANIELRAJ, 2016). As such, rework
have critically influenced the productivity, performance, and finance of a
project (ANIL; DANIELRAJ, 2016).
3. METHODOLOGY
Quantitative research approach was
adopted for data collection, and well-structured questionnaires were used to collect
data on the perception of the various professionals regarding the factors that
trigger the emergence of construction rework. The questionnaire was self-
administered, by the authors and through the help of trained field assistants
who were properly briefed about the research topic and given the necessary
information on how to administer the questionnaire
The appropriateness of the
questionnaire to meet the study objectives was carried out through a pilot
survey. Fellows and Liu (2008) opined that research instrument (questionnaire)
should be initially piloted in order to verify whether the questions are
intelligible, unambiguous and easy to answer, as well as providing an
opportunity to improve the questionnaire and determining the time required in completing
the exercise. Twenty (20) of the draft questionnaire were randomly distributed
to selected construction professionals, and the final draft was adjusted based
on their feedback.
The populations of the study are
registered professionals such as: Builders,
Quantity surveyors, Architects, and Engineers practicing within Abuja, Nigeria.
The total population of this study is 6899 comprising (404 builders, 845
Quantity surveyors, 400 Architects and 5250 Engineers). This number was
obtained from the register of Abuja chapter of the various professional bodies namely Nigerian
Institute of Building (NIOB) for builders, Nigerian Institute of Architects
(NIA) for the architects, Nigerian Institute of Quantity Surveyors (NIQS) for
quantity surveyors, and Nigerian Society of Engineer (NSE) for engineers. Abuja
was selected for this study because it is the administrative headquarters of
Nigeria; and it is one of the metropolitan cities in Nigeria with the highest
population of Construction professionals practicing in either constructing or
consulting firms within the built environment (SAIDU; SHAKANTU, 2016c).
The
sample size for this study is 364, and this was derived by applying the formula
by The NEA Research Bulletin (1960), and Krejcie and Morgan (1970) to the
population using a 95% confidence level.
s
= X 2 NP (1 − P) ÷ d 2 (N − 1) + X 2 P (1 − P) (1)
Where;
s = sample size from
finite population
X = based on confidence level 1.96 for 95% confidence was used for this
study
d = Precision desired, expressed as a decimal (i.e. 0.05 for 5% used for
this study
P = Estimated variance in Population as a decimal (i.e. 0.5 for this
study)
N= total number of population
A total of 195 questionnaires were
retrieved out of the 364 distributed. Out of the 195 response received, seven
(7) were invalid because of incomplete response, and 188 were properly filled
and was considered valid response, this represents a response rate of 51.64%.
The 188 valid responses consist of 32 builders, 61 quantity surveyor, 44
Architects, and 51 civil engineers. According to Alreck and Settle (1985), this
response rate is considered suitable for a study whose focus is to gain
responses from professionals and practitioners within the construction
industry.
The questionnaire was based on a
5-point Likert scale and ranges from 1 to 5, with 5 being the highest. The analysis of the data collected was
carried out using means item score, percentages, Kruskal-Wallis H test. Tables
and charts were also used to present the analyzed data. Mean item score was used
to analyze and rank the factors that trigger rework incidences. Kruskal-Wallis
H test was used to test the hypotheses in order to determine if there are
statistically significant differences in the opinions of the respondents.
Kruskal-Wallis test was also adopted to ascertain the variables in which the
respondents view varies. The rule for accepting or rejecting the hypothesis is;
i.
accept
hypothesis; if P-value ≥0.05, and
ii.
reject
hypothesis; if P-value <0.05.
These analyses were done using
statistical package for social science (SPSS) Version 20
4. 4. RESULTS AND DISCUSSIONS
4.1.
General
Information of Respondents
The
analysis of respondents’ information revealed that 48.40% of the respondents
have their years of experience rage from 1-10 years, and 39.89% have work in
the construction industry for 11-20 years. This implies that they are
experienced enough to give reliable information that will aid the study. In
addition, 29.79% of the respondents have diploma degree, 46.28% have Bsc/B.Tech
degree and 21.81% of them are master’s degree holders. This implies that they
are academically qualified to take active part in this study.
Furthermore,
according to the respondents, 73.4% always keep records of rework incidents,
23.94% keeps record sometimes, and only 2.66% of them had never kept rework of
rework incidences. Rework incidences cannot
be completely attributable to a particular party, they respondents are of the
opinion that the activities of contractors contribute most to rework with
37.77%, and that is closely followed by the consultant (31.38%) and then the
client/customer (18.09%).
Also,
the professional qualification of the respondents indicates that, 32.45% of
them are quantity surveyors and are registered with the Nigerian Institute of
Quantity Surveyors (NIQS), 17.02% are builders and are registered with Nigerian
Institute of Builders (NIOB), 23.40% are Architects and belong to Nigerian
Institute of architects (NIA), and 27.13% are Engineers and are members of
Nigerian Society of Engineers (NSE).
The
high proportion of quantity surveyors implies that they are involved in
cost-associated matters such as rework in the construction industry. Similarly,
the professional status of the respondents shows that, 21.81% of the
respondents are probationer members of the various professional bodies, 76.06%
are corporate members of the various professional bodies, and 2.13% are fellows
of the professional bodies. The high proportion of the corporates members
indicates that the respondents are professionally qualified to give an expert
opinion on the subject of this study.
4.2.
Normality
Test for Rework Risks Triggers
A
normality test was first carried out on the collected data in order to
determine the type of test to be done. The essence was to establish the nature
of the data (i.e. whether it is parametric or non-parametric). To ascertain
this, Ghasemi and Zahediasi (2012) suggested the use of Shapiro-Wilk normality
test in studies with sample size of less than 2000.
The
analysis shows that the significant value of all the variables examined is
0.000, which is less than the 0.05 required criteria for normality. Therefore,
the collected data are non-parametric in nature and cannot be examined using
normal parametric statistical techniques. This confirms the recommendation of
Thode (2002) that Shapiro-Wilk test is the best choice for testing the
normality of non-parametric data.
Thus,
Kruskal-Walis test; a non-parametric test, which is suitable when there is need
to ascertain the significant difference in the perception of three or more
categories of respondents, was employed in determining consistency in the
opinion of the respondents within the four (4) different professions in the
built environment.
4.3.
Comparation
of Professionals Perception Regarding Rework Risks Triggers
Table
1 shows the significant value derived from Kruskal-Wallis H test conducted on
rework risks triggers on building construction projects. Kruskal-Wallis H test
was used to compare the perceptions of construction professionals regarding the
rework risks trigger on construction projects. Under the client-related
factors, the result revealed that the p-value of one (1) out of the 7 risks
factors assessed is less than 0.05.
This
implies that there is a significant difference in the way these respondents
from the different professions in the construction industry view this factor.
This factor is lack of adequate participation of the client in the project. This
difference in view could be attributed to the individual perception of
construction professionals as to the level and experience of the client in
construction activities.
The
professionals are of the opinion that the engagement of the consultant should
relief the client of the responsibility of participating fully in the project,
as he may be busy with other investments. However, it is observed that there is
a significant relationship in the perception of the respondents on other rework
risks triggers as the have their P-value to be greater than 0.05.
This
result is in consonance with the report of Enshassi et al., (2017), who found
out that construction experts agrees on the owner related rework causes, as the
probability of significance was more than 0.05. Simpeh (2012), also, reported a
level of agreement among respondents concerning some client-related factors
that contribute to rework.
Similarly,
changes requested by the client with a p-value of less than 0.05, was the only
rework risks trigger among the design-related factors in which the perceptions
of the categories of professionals differs significantly. The respondents are
of the opinion that, although, the client is a major stakeholder and the
financier of the project, the design consultants should be able to influence
the number and frequencies of changes requested by the client.
Implying
that the consultants are in the best position to advise the clients on various
design options. Conversely, the perception of other rework triggers were
observed to be significant and in agreement as their P-value > 0.05.
Implying that these design-related factors influences the emergence of
construction rework which could impact on construction time, cost and
resources. This finding is supported by Enshassi et al., (2017), who reported
that there is agreement among construction participants on the probability of
occurrence of rework causes related to design.
Evidently,
respondents were in disagreement about six (6) factors under the contractor-related
factors. These factors are errors in setting out,
inadequate training and inexperience, poor planning of resources, lack of
protection of completed work, excessive overtime, and non-compliance with
specification.
The
analysis revealed that
these factors had p-values < 0.05, implying a significant difference in the
professionals perception of these factors. The p-value of the remaining 15
rework risks triggers were observed to be greater than 0.05, implying a
non-significant difference in the opinion of the respondents. This finding is
in disagreement with Simpeh (2012) and in agreement with Enshassi et al.,
(2017).
Simpeh
(2012) reported a level of agreement among respondents for all the factors
considered to be subcontractors-related contributors rework. Enshassi et al.,
(2017) reported p-value of 0.028, which implies that, there is a level of
disagreement among construction participants on contractors-related causes of
rework in Palestine. The level of disagreement observed in this study could be
attributed to the differences in what the professionals understands to be basic
contractual requirements of a contract and the contractor.
The
respondents maybe of the view that a contractor who cannot set-out a building
line, should not take up construction job in the first place. Also, that there
is no need being in construction business when a contract specification cannot
be adequately followed. A clear project method statement should detail the
requirements for protecting construction work.
Under
the environmental-related causes, the result revealed that the p-values of one
(1) out of the 6 risks factors assessed is less than 0.05, which implies that
there is a significant difference in the way these respondents from the
different professions in the construction industry view this factor. This
factor is damage due to weather conditions.
This
difference in view could be attributed to the need to be sensitive to seasons
or periods of the year in which construction activities can be smoothly be
carried out without drawbacks. In Nigeria for instance, construction works are
better during the dry season than in raining season. However, it is observed
that there is a significant relationship in the perception of the respondents
on other rework risks triggers under the environmental related causes, as their
P-value > 0.05.
Table
1: Comparation of Professionals Perception Regarding Rework Risks Triggers on
building construction projects |
||||||
Factors |
Mean Rank |
P-value |
Decision |
|||
Bldr. |
Q. S |
Arch. |
Engr. |
|||
Client-related factors |
||||||
Poor communication with the architect and
engineers (design consultants) |
93.22 |
102.57 |
88.60 |
90.74 |
0.5040 |
Accept |
Lack of knowledge and inexperience in project design development |
98.48 |
97.53 |
86.95 |
94.88 |
0.7210 |
Accept |
Lack of knowledge and inexperience of the
construction process |
83.86 |
96.83 |
96.19 |
96.93 |
0.6540 |
Accept |
Inadequate time and money spent during
project brief development |
97.55 |
95.16 |
90.12 |
95.57 |
0.9290 |
Accept |
Insufficient fund allocated to site
investigations |
97.20 |
99.20 |
77.99 |
101.42 |
0.1190 |
Accept |
Lack of adequate participation of the
client in the project |
122.19 |
94.68 |
76.41 |
92.52 |
0.0030* |
Reject |
Low fee payment for preparing contract
documents |
90.94 |
92.22 |
95.49 |
98.61 |
0.8980 |
Accept |
Design-related factors |
||||||
Changes requested by the client |
127.19 |
90.65 |
80.73 |
90.48 |
0.0010* |
Reject |
Design not completed at tender time |
99.22 |
93.02 |
96.09 |
91.93 |
0.9210 |
Accept |
Items omission from the contract documents |
108.91 |
91.06 |
100.82 |
84.13 |
0.1350 |
Accept |
Poor design coordination |
104.31 |
94.13 |
94.38 |
88.89 |
0.6280 |
Accept |
Contractor initiated changes during
construction |
95.78 |
97.96 |
92.90 |
90.94 |
0.9030 |
Accept |
Mistakes and Errors discovered in the contract documents |
100.16 |
93.24 |
101.66 |
86.28 |
0.4620 |
Accept |
Inadequate time devoted for preparing
contract documents |
97.27 |
93.25 |
98.25 |
91.03 |
0.9030 |
Accept |
Time boxing (i.e. fixed time for completing
task) |
76.28 |
100.52 |
98.80 |
95.02 |
0.1810 |
Accept |
insufficient client brief for preparing detailed contract documents |
91.97 |
101.05 |
92.31 |
90.15 |
0.6980 |
Accept |
Deficiency of required skills for
completing task |
92.84 |
97.20 |
95.34 |
91.58 |
0.9440 |
Accept |
Poor workload planning |
77.83 |
102.82 |
94.85 |
94.71 |
0.1830 |
Accept |
Consultant's Ineffective use of quality
management practices |
110.83 |
87.35 |
84.55 |
101.39 |
0.0850 |
Accept |
Ineffective use of information technologies |
77.53 |
105.84 |
92.68 |
93.15 |
0.0920 |
Accept |
Contractor-related factors |
||||||
Errors in Setting out |
109.91 |
104.01 |
97.58 |
70.80 |
0.0010* |
Reject |
Inadequate
training and inexperience |
120.39 |
95.90 |
87.61 |
82.52 |
0.0090* |
Reject |
Poor coordination of resources (e.g.
subcontractors) |
87.94 |
96.62 |
92.77 |
97.57 |
0.8350 |
Accept |
Constructability problems |
83.16 |
107.07 |
87.59 |
92.54 |
0.1090 |
Accept |
Contractor's Ineffective use of quality
management practices |
101.59 |
92.04 |
85.82 |
100.48 |
0.4020 |
Accept |
Poor planning of resources |
128.69 |
86.45 |
87.62 |
88.61 |
0.0010* |
Reject |
Lack of protection of completed work |
122.78 |
88.59 |
88.22 |
89.25 |
0.0100* |
Reject |
Lack of safety |
91.12 |
94.96 |
96.53 |
94.31 |
0.9780 |
Accept |
Excessive overtime |
99.83 |
89.41 |
79.11 |
110.52 |
0.0230* |
Reject |
Non-compliance with specification |
111.33 |
104.92 |
94.18 |
71.75 |
0.0010* |
Reject |
Low labour skill level |
97.39 |
93.40 |
99.09 |
90.04 |
0.8400 |
Accept |
Shortage of skilled labour |
87.97 |
92.57 |
100.81 |
95.47 |
0.7440 |
Accept |
Staff Turnover |
88.00 |
95.50 |
96.16 |
95.95 |
0.8920 |
Accept |
Shortage of skilled supervisors |
92.11 |
92.94 |
100.44 |
92.74 |
0.8280 |
Accept |
Defective workmanship |
100.12 |
99.24 |
84.88 |
93.61 |
0.4760 |
Accept |
Inadequate Supervisor / Foreman /Tradesmen
ratios |
85.83 |
100.20 |
90.06 |
96.95 |
0.5480 |
Accept |
Damages to work due to carelessness |
102.86 |
90.11 |
97.93 |
91.54 |
0.6650 |
Accept |
Unclear instruction to workers |
103.75 |
88.12 |
95.61 |
95.36 |
0.5130 |
Accept |
change
in construction methods
cause by site conditions |
88.45 |
97.41 |
94.65 |
94.69 |
0.8920 |
Accept |
incomplete and inaccurate information |
105.88 |
85.65 |
98.67 |
94.35 |
0.1700 |
Accept |
Machine breakdown or defects |
86.62 |
98.29 |
94.11 |
95.25 |
0.7890 |
Accept |
Environmental-related causes |
||||||
Changes initiated by the
municipality/regulatory bodies |
83.25 |
90.88 |
90.94 |
108.96 |
0.1250 |
Accept |
Change in design due to economic changes |
109.98 |
95.97 |
95.36 |
82.28 |
0.1370 |
Accept |
design change initiated due to social
changes |
99.95 |
98.66 |
97.65 |
83.39 |
0.3710 |
Accept |
design change initiated due to legal changes |
105.44 |
84.53 |
104.18 |
91.21 |
0.1500 |
Accept |
Damage due to weather conditions |
115.73 |
90.61 |
99.61 |
81.41 |
0.0280* |
Reject |
Damage due to natural disasters |
93.88 |
96.14 |
98.85 |
89.18 |
0.8250 |
Accept |
N = 32 for Building (Bldr.), N = 61 for
Quantity Surveyor (Q.S), N = 44 for Architect (Arch.), N = 51 for Engineering
(Engr.) , df = 3 |
4.4.
Rework
Risks Triggers on building construction projects
Table
2 shows the result of the analysis
and ranks of the respondents’ response on the extent to which the identified
rework triggers contribute to rework occurrences in the construction industry;
using the 5-points Likert scale below, where
1 = very Low, 2 = Low, 3 =
Average, 4 = High, 5 = very High.
Under
client-related category; the Builders are of the opined that the top four
factors that triggers the emergence of rework are Poor
communication with the architect and engineers (design consultants) ranked 1st,
Inadequate time and money spent during project brief development ranked 2nd,
Lack of knowledge and inexperience in project design development, and
Insufficient fund allocated to site investigations which ranked 3rd
each.
The Quantity surveyors ranked Poor
communication with the architect and engineers (design consultants) as 1st,
Lack of knowledge and inexperience in project design development as 2nd
, Inadequate time and money spent during project brief development, and
Insufficient fund allocated to site investigations were each ranked 3rd.
According to the Architects, the top
factors that trigger rework are Poor communication with the architect and
engineers (design consultants), Lack of knowledge and inexperience of the
construction process, Low fee payment for preparing contract documents, Lack of
knowledge and inexperience in project design development which ranked 1st,
2nd ,3rd and 4th respectively.
The engineers ranked Insufficient
fund allocated to site investigations 1st, Lack of knowledge
and inexperience in project design development, and Inadequate
time and money spent during project brief development were each ranked 2nd and Poor
communication with the architect and engineers (design consultants) was ranked 4th.
On the overall, the top rework
triggers that are related to the client are Poor communication with the
architect and engineers (design consultants), Inadequate time and money spent
during project brief development, Lack of knowledge and inexperience
in project design development, and Insufficient fund allocated to site
investigations which ranked 1st, 2nd, 3rd, and
4th respectively.
This result corroborates the
findings of (MAHAMID, 2016; ENSHASSi et al., 2017; PALANEESWARAN, 2006).
Mahamid (2016) reported that poor
communication with the contract, poor communication with the design consultant,
lack of client involvement in the project and lack of funding allocated for
site investigation; are factors with high severity index that may lead to late materials and
specifications changes during the project’s construction phase that could
result to rework.
Palaneeswaran (2006) specified that the
main causes of owner related rework are lack of knowledge of design and
construction process, insufficient fund allocated for site investigation, lack
of client involvement throughout the project, inadequate briefing, poor
communication with design consultants; and inadequacies in contract documentation.
Enshassi
et al., (2017) found out that inadequate briefing, lack of knowledge of
construction process, lack of funding allocated for site investigation, change
due to change of officials, and lack of funding allocated for consultation; are
the major owner causes of rework that impact on the time and cost of
construction projects.
Therefore, Simpeh (2012) observed that these client-related factors are
significant correlated to the impact of rework on project performance.
For
the design-related category; the Builders are of the opined that the top five
factors that triggers the emergence of rework are Items
omission from the contract documents ranked 1st, Changes requested
by the client ranked 2nd, Mistakes and Errors discovered in the contract documents ranked 3rd
, Design not completed at tender time,
Poor design coordination and Deficiency of required skills for completing task
ranked 4th each.
The Quantity surveyors ranked
Deficiency of required skills for completing task, Design not completed at
tender time, Items omission from the contract documents, Mistakes and
Errors discovered in the contract
documents, and Contractor initiated changes during construction as 1st,
2nd, 3rd, 4th and 5th respectively.
According to the Architects, the top
five factors that trigger rework are Items omission from the contract
documents, and Mistakes and Errors discovered in the contract documents each
ranked 1st, Deficiency of required skills for completing task,
Design not completed at tender time and Poor design coordination which ranked 3rd,
4th and 5th respectively.
The engineers ranked Deficiency of
required skills for completing task, Design not completed at tender time, Items
omission from the contract documents, Mistakes and Errors discovered in the
contract documents, and Poor design coordination as 1st, 2nd,
3rd, 4th and 5th respectively.
While on the overall, the top five
factors that are related to design that triggers rework are Items omission from
the contract documents, Deficiency of required skills for completing task,
Design not completed at tender time, Mistakes and Errors discovered in the
contract documents, and Poor design coordination which ranked 1st, 2nd,
3rd, 4th and 5th respectively. This result is
consistent with the findings of (SIMPEH, 2012; MAHAMID 2016; ENSHASSI et al.,
2017).
Simpeh (2012) found out that the
most prominent source of design induced rework are changes made at the request
of the client, incomplete design at the time of tender, and omission of items
from the contract documents. Enshassi et al. (2017) reported that design errors
and omission, incomplete information for design, incomplete design, and lack of
professionalism are major factors related to design that have high impact on
project performance.
According to Mahamid (2016), late
design changes, errors and omissions and lack of designers’ experience are the
top three causes of rework related to design consultants. These factors have a
very wide impact on
project performance (MAHAMID 2017; ENSHASSI et al. 2017; JOSEPHSON et
al., 2002). This
result is also in agreement with (LOVE et al., 1999; JOSEPHSON et
al., 2002).
Love
et al., (1999) stressed that insufficiently advanced contract documents is a
consequent of inadequate information and limited time allocated to design
related activities which may lead to rework. Love et al. (1999) further stated
that the focus of solving site problems due to design errors inversely
influences productivity, performance and production cost, whilst rework impact
directly on production cost.
Josephson
et al. (2002) are
of the opinion that design causes that are capable of causing rework are
incomplete designs, inadequate information for design, and lack of
professionalism. Oyewobi and Ogunsemi (2010) advocated the need for
unity among all stakeholders so that the design process will be properly
coordinated and workable plan put in place to prevent rework emergence.
For
the contractor-related category; the Builders are of the opined that the top
five factors that triggers the emergence of rework are incomplete
and inaccurate information, Unclear instruction to workers, Errors in Setting
out, Shortage of skilled supervisors, and Non-compliance with
specification which ranked 1st,
2nd, 3rd, 4th and 5th respectively.
The Quantity surveyors ranked
Shortage of skilled supervisors, Errors in Setting out, Unclear instruction to
workers as 1st, 2nd and 3rd respectively, and
Constructability problems, and Non-compliance with specification occupied 4th
position each.
According to the Architects, the top
five factors that trigger rework are Shortage of skilled supervisors, Unclear
instruction to workers, incomplete and inaccurate information, Errors in
Setting out , and Non-compliance with specification which ranked 1st,
2nd, 3rd, 4th and 5th respectively.
The engineers ranked Unclear instruction to workers, Shortage of skilled
supervisors, Contractor's Ineffective use of quality management practices,
incomplete and inaccurate information, and Excessive overtime as 1st,
2nd, 3rd, 4th and 5th respectively.
The overall ranking of the top five
contractors-related factors that triggers rework are Unclear instruction to
workers, Shortage of skilled supervisors, incomplete and inaccurate
information, Errors in Setting out, and Contractor's Ineffective use of quality
management practices which ranked 1st, 2nd, 3rd,
4th and 5th respectively. This report is supported by (ENSHASSI et al., 2017; MAHAMID,
2016; SIMPEH, 2012).
Mahamid
(2016) reported that the top six contractor related causes of rework are Poor
communication with the consultant, Use of poor quality material, Poor site
management, Improper subcontractor selection, Use of inefficient equipment, and
Ineffective use of quality control system. Causes under the contractors groups have
wide severity index and their impact ranges from moderate to high.
Enshassi
et al. (2017) concluded that poor quality system by the contract With RII of
78.2%, result to rework and has a considerable impact on project cost and time.
Simpeh (2012) stated that setting out errors, lack of training and experience,
poor coordination of subcontractors, non-compliance with specification by the
subcontractors, low labour skill level and shortage of skilled labour are the
major factors responsible for rework under site management factors and
subcontractor-related factors.
It
is clear that the management and coordination of the site and subcontractors
are the responsibility of the main contractors. Oyewobi and Ogunsemi (2010)
made an assertion which implies that buildings can be constructed free of
rework when there is adequate and non-conflicting information.
Under
the environmental–related category, the Builders are of the opined that the top
three factors that triggers the emergence of rework are Damage due to
weather conditions, Change in design due to economic changes, and design change
initiated due to social changes which ranked 1st, 2nd and
3rd respectively.
The Quantity surveyors ranked Change
in design due to economic changes, design change initiated due to social
changes, and Damage due to weather conditions as 1st, 2nd,
and 3rd respectively.
According to the Architects, the top three factors that trigger rework
Damage due to weather conditions, Change in design due to economic changes, and
Damage due to natural disasters, which ranked 1st, 2nd
and 3rd respectively.
The engineers ranked Changes
initiated by the municipality/regulatory bodies, Damage due to weather
conditions, and Damage due to natural disasters as 1st, 2nd
and 3rd respectively.
While on the overall, the top three
factors that are related to Damage due to weather conditions, Change in design
due to economic changes, and Changes initiated by the municipality/regulatory
bodies, which ranked 1st, 2nd, and 3rd
respectively. This
result is supported by (ENSHASSI et al., 2017; MAHAMID, 2016; MASTENBROEK, 2010).
Enshassi
et al. (2017) found out that political situation, economy (i.e. exchange rate, inflation, market
condition), and physical infrastructures are the critical environmental factors
that influence the occurrence of rework. Mahami (2016) reported that causes
with high severity index that are related to external environmental factors are
weather and lack of safety. External environmental factors are factors beyond
the control of project participants (MOHAMED, 2015; OMRAN
et al., 2012).
According to Omran
et al., (2012), the three external environment factors that influence
construction projects performance
are economic environment factors,
political environment, and social environment,
which were ranked 1st, 2nd and 3rd
respectively.
Mahami (2016) argue that environmental factors have low to moderate impact on
project performance. Construction rework could result from weather conditions,
disasters from natural forces, or changes in
external environment (MASTENBROEK,
2010).
Table
2: Rework Risks Triggers on Building Construction Projects |
||||||||||
Factors |
Bldr |
Q. S |
Arch. |
Engr |
Overall |
|||||
MIS |
Rk. |
MIS |
Rk. |
MIS |
Rk. |
MIS |
Rk. |
MIS |
Rk. |
|
Client-related factors |
|
|
|
|
|
|
|
|
|
|
Poor communication with the architect and
engineers (design consultants) |
3.91 |
1 |
4.00 |
1 |
3.91 |
1 |
3.88 |
4 |
3.92 |
1 |
Lack of knowledge and inexperience in project design development |
3.81 |
3 |
3.89 |
2 |
3.73 |
4 |
3.92 |
2 |
3.83 |
3 |
Lack of knowledge and inexperience of the
construction process |
3.44 |
7 |
3.75 |
5 |
3.84 |
2 |
3.86 |
5 |
3.72 |
5 |
Inadequate time and money spent during project
brief development |
3.88 |
2 |
3.85 |
3 |
3.71 |
5 |
3.92 |
2 |
3.84 |
2 |
Insufficient fund allocated to site
investigations |
3.81 |
3 |
3.85 |
3 |
3.32 |
6 |
3.96 |
1 |
3.74 |
4 |
Lack of adequate participation of the client in
the project |
3.72 |
5 |
3.03 |
7 |
2.61 |
7 |
3.00 |
7 |
3.09 |
7 |
Low fee payment for preparing contract documents |
3.56 |
6 |
3.64 |
6 |
3.75 |
3 |
3.82 |
6 |
3.69 |
6 |
Design-related factors |
||||||||||
Changes requested by the client |
4.28 |
2 |
3.48 |
10 |
3.27 |
10 |
3.49 |
10 |
3.63 |
9 |
Design not completed at tender time |
4.03 |
4 |
4.03 |
2 |
4.07 |
4 |
4.00 |
2 |
4.03 |
3 |
Items omission from the contract documents |
4.31 |
1 |
4.02 |
3 |
4.16 |
1 |
3.90 |
3 |
4.10 |
1 |
Poor design coordination |
4.03 |
4 |
3.84 |
8 |
3.86 |
5 |
3.78 |
5 |
3.88 |
5 |
Contractor initiated changes during construction |
3.84 |
8 |
3.97 |
5 |
3.75 |
6 |
3.73 |
7 |
3.82 |
6 |
Mistakes and Errors discovered in the contract documents |
4.09 |
3 |
3.98 |
4 |
4.16 |
1 |
3.86 |
4 |
4.02 |
4 |
Inadequate time devoted for preparing contract
documents |
3.44 |
9 |
3.49 |
9 |
3.61 |
9 |
3.45 |
11 |
3.50 |
11 |
Time boxing (i.e. fixed time for completing task) |
2.56 |
13 |
3.31 |
12 |
3.25 |
12 |
3.14 |
12 |
3.07 |
13 |
insufficient client brief for preparing detailed contract documents |
3.00 |
12 |
3.31 |
12 |
3.07 |
13 |
3.00 |
13 |
3.09 |
12 |
Deficiency of required skills for completing task |
4.03 |
4 |
4.15 |
1 |
4.11 |
3 |
4.06 |
1 |
4.09 |
2 |
Poor workload planning |
3.34 |
10 |
3.87 |
7 |
3.73 |
7 |
3.73 |
7 |
3.67 |
7 |
Consultant's Ineffective use of quality
management practices |
4.00 |
7 |
3.33 |
11 |
3.27 |
10 |
3.75 |
6 |
3.59 |
10 |
Ineffective use of information technologies |
3.31 |
11 |
3.89 |
6 |
3.66 |
8 |
3.67 |
9 |
3.63 |
8 |
Contractor-related factors |
||||||||||
Errors in Setting out |
4.47 |
3 |
4.39 |
2 |
4.27 |
4 |
3.76 |
10 |
4.22 |
4 |
Inadequate
training and inexperience |
3.41 |
18 |
3.02 |
21 |
2.80 |
21 |
2.73 |
21 |
2.99 |
21 |
Poor coordination of resources (e.g.
subcontractors) |
3.94 |
10 |
4.07 |
10 |
4.00 |
6 |
4.08 |
8 |
4.02 |
9 |
Constructability problems |
3.81 |
12 |
4.28 |
4 |
3.91 |
10 |
4.00 |
9 |
4.00 |
10 |
Contractor's Ineffective use of quality
management practices |
4.22 |
7 |
4.18 |
7 |
3.98 |
8 |
4.31 |
3 |
4.17 |
5 |
Poor planning of resources |
4.09 |
9 |
3.23 |
18 |
3.25 |
19 |
3.27 |
18 |
3.46 |
17 |
Lack of protection of completed work |
4.19 |
8 |
3.52 |
14 |
3.50 |
15 |
3.53 |
15 |
3.69 |
12 |
Lack of safety |
2.94 |
21 |
3.03 |
20 |
3.07 |
20 |
3.02 |
20 |
3.01 |
20 |
Excessive overtime |
3.78 |
13 |
3.51 |
16 |
3.45 |
16 |
4.18 |
5 |
3.73 |
11 |
Non-compliance with specification |
4.28 |
5 |
4.28 |
4 |
4.07 |
5 |
3.61 |
13 |
4.06 |
7 |
Low labour skill level |
3.59 |
14 |
3.52 |
14 |
3.64 |
12 |
3.45 |
16 |
3.55 |
15 |
Shortage of skilled labour |
3.47 |
16 |
3.54 |
13 |
3.75 |
11 |
3.63 |
12 |
3.60 |
14 |
Staff Turnover |
3.41 |
18 |
3.59 |
12 |
3.59 |
14 |
3.59 |
14 |
3.54 |
16 |
Shortage of skilled supervisors |
4.31 |
4 |
4.41 |
1 |
4.50 |
1 |
4.39 |
2 |
4.40 |
2 |
Defective workmanship |
4.25 |
6 |
4.21 |
6 |
3.98 |
8 |
4.12 |
6 |
4.14 |
6 |
Inadequate Supervisor / Foreman /Tradesmen ratios |
3.91 |
11 |
4.16 |
8 |
4.00 |
6 |
4.12 |
6 |
4.05 |
8 |
Damages to work due to carelessness |
3.47 |
16 |
3.18 |
19 |
3.36 |
18 |
3.22 |
19 |
3.31 |
19 |
Unclear instruction to workers |
4.59 |
2 |
4.31 |
3 |
4.45 |
2 |
4.45 |
1 |
4.45 |
1 |
change
in construction methods
cause by site conditions |
3.50 |
15 |
3.70 |
11 |
3.64 |
12 |
3.65 |
11 |
3.62 |
13 |
incomplete and inaccurate information |
4.63 |
1 |
4.10 |
9 |
4.41 |
3 |
4.29 |
4 |
4.36 |
3 |
Machine breakdown or defects |
3.28 |
20 |
3.51 |
16 |
3.43 |
17 |
3.45 |
16 |
3.42 |
18 |
Environmental-related causes |
||||||||||
Changes initiated by the municipality/regulatory
bodies |
2.84 |
6 |
3.10 |
4 |
3.09 |
5 |
3.53 |
1 |
3.14 |
3 |
Change in design due to economic changes |
3.59 |
2 |
3.26 |
1 |
3.25 |
2 |
2.96 |
4 |
3.27 |
2 |
design change initiated due to social changes |
3.22 |
3 |
3.21 |
2 |
3.16 |
4 |
2.86 |
5 |
3.11 |
4 |
design change
initiated due to legal changes |
3.00 |
5 |
2.57 |
6 |
2.98 |
6 |
2.71 |
6 |
2.81 |
6 |
Damage due to weather conditions |
3.75 |
1 |
3.20 |
3 |
3.39 |
1 |
3.00 |
2 |
3.33 |
1 |
Damage due to natural disasters |
3.06 |
4 |
3.10 |
4 |
3.23 |
3 |
2.98 |
3 |
3.09 |
5 |
Bldr. = Builder; Q. S = Quantity Surveyor;
Arch. = Architect; Engr. Engineer; Rk = Rank |
4.5.
Category
of Rework Risks Triggers
Table
3 shows the major categories of rework risks factors. According to the results,
rework risks triggers that are related to the contractor was ranked first in
the group with overall (MIS=3.80), implying that the contractors are
responsible for majority of the rework incidences in construction projects.
This
finding is supported by statement of Enshassi et al. (2017), which implied that
contractors are the highest contributor to rework occurrence and their
activities have high impact on project overall performance. This result
corroborates the findings of (LOVE; EDWARDS, 2004a; LOVE et al., 1999;
PALANEESWARAN, 2006; SIMPEH, 2012).
Rework
risk factors related to design factors was ranked second in the group with (MIS
= 3.70), implying second highest cause of rework and high impact on project
success. Client-related factors that
trigger the occurrence of rework was ranked third with (MIS = 3.69) and the
Environmental-related causes was ranked forth with (MIS=3.13).
This
result is supported by (MAHAMID, 2016; LOVE et al., 1999; PALANEESWARAN, 2006;
ENSHASSI et al., 2017; SIMPEH, 2012). Since, each of the group have their MIS
>3.0, it means that their activities either at design or construction stage
have significant impact on the emergence of rework.
Table 3: Category of
Rework Risks Triggers |
|||||||
S/No |
Category of Rework Risks Triggers |
Average MIS |
Overall |
Rank |
|||
Bldr. |
Q. S |
Arch. |
Engr. |
||||
1 |
Client-related
factors |
3.73 |
3.72 |
3.56 |
3.77 |
3.69 |
3 |
2 |
Design-related
factors |
3.71 |
3.74 |
3.69 |
3.66 |
3.70 |
2 |
3 |
Contractor-related
factors |
3.88 |
3.80 |
3.76 |
3.75 |
3.80 |
1 |
4 |
Environmental-related
cause |
3.24 |
3.07 |
3.18 |
3.01 |
3.13 |
4 |
Bldr. = Builder; Q. S = Quantity Surveyor; Arch. = Architect; Engr.
Engineer; Rk = Rank
4.6.
Fifteen
most important rework risks triggers on building construction projects
Table
4 displays a summary of the top fifteen (15) rework risks triggers from the
overall rework triggers on Table 2. From the overall rank on column 11, rework
factors that are ranked from 1st – 5th are related to the
activities of the contractors.
From
factors on 6th to 9th are design-related factors, which
are the major responsibilities of the consultants, and the 10th
factor is related to the client. The two last factors, 14th – 15th
are related to the external environment of the project.
It
is evident that the majority of the top fifteen rework triggers emerges from
the activities, weaknesses and inefficiencies of the contractor. This finding
further supported the result on Table 3, and the reports of previous
researchers (AJAYI; OYEYIPO, 2015; ENSHASSI et al., 2017; LOVE; EDWARDS, 2004a; LOVE et
al.,1999; MAHAMID, 2016; PALANEESWARAN, 2006; SIMPEH, 2012).
Table 4: Top Fifteen
(15) Rework Risks Triggers on building construction projects |
||||||||||
Factors |
Bldr |
Q. S |
Arch. |
Engr |
Overall |
|||||
MIS |
Rk. |
MIS |
Rk. |
MIS |
Rk. |
MIS |
Rk. |
MIS |
Rk. |
|
Poor
communication with the architect and engineers (design consultants) |
3.91 |
11 |
4.00 |
9 |
3.91 |
10 |
3.88 |
10 |
3.92 |
10 |
Lack of
knowledge and inexperience in project design development |
3.81 |
13 |
3.89 |
11 |
3.73 |
12 |
3.92 |
7 |
3.83 |
13 |
Inadequate
time and money spent during project brief development |
3.88 |
12 |
3.85 |
12 |
3.71 |
13 |
3.92 |
7 |
3.84 |
12 |
Design not
completed at tender time |
4.03 |
8 |
4.03 |
7 |
4.07 |
8 |
4.00 |
6 |
4.03 |
8 |
Items
omission from the contract documents |
4.31 |
4 |
4.02 |
8 |
4.16 |
5 |
3.90 |
9 |
4.10 |
6 |
Poor design
coordination |
4.03 |
8 |
3.84 |
13 |
3.86 |
11 |
3.78 |
12 |
3.88 |
11 |
Mistakes and
Errors discovered in the contract
documents |
4.09 |
7 |
3.98 |
10 |
4.16 |
5 |
3.86 |
11 |
4.02 |
9 |
Deficiency
of required skills for completing task |
4.03 |
8 |
4.15 |
5 |
4.11 |
7 |
4.06 |
5 |
4.09 |
7 |
Errors in
Setting out |
4.47 |
3 |
4.39 |
2 |
4.27 |
4 |
3.76 |
13 |
4.22 |
4 |
Contractor's
Ineffective use of quality management practices |
4.22 |
6 |
4.18 |
4 |
3.98 |
9 |
4.31 |
3 |
4.17 |
5 |
Shortage of
skilled supervisors |
4.31 |
4 |
4.41 |
1 |
4.50 |
1 |
4.39 |
2 |
4.40 |
2 |
Unclear
instruction to workers |
4.59 |
2 |
4.31 |
3 |
4.45 |
2 |
4.45 |
1 |
4.45 |
1 |
incomplete
and inaccurate information |
4.63 |
1 |
4.10 |
6 |
4.41 |
3 |
4.29 |
4 |
4.36 |
3 |
Change in
design due to economic changes |
3.59 |
15 |
3.26 |
14 |
3.25 |
15 |
2.96 |
15 |
3.27 |
15 |
Damage due
to weather conditions |
3.75 |
14 |
3.20 |
15 |
3.39 |
14 |
3.00 |
14 |
3.33 |
14 |
Bldr. = Builder; Q. S = Quantity Surveyor; Arch. = Architect; Engr.
Engineer; Rk = Rank |
5. CONCLUSION AND RECOMMENDATIONS
Based
on the findings, it was concluded that rework factors related to the
contractor's activities and those related to the activities of the design
consultants are the major categories of rework risks triggers. Furthermore, it
was concluded that unclear instruction to workers, Shortage of skilled
supervisors, incomplete and inaccurate information, Errors in Setting out, and
Contractor's Ineffective use of quality management practices are the main
triggers of rework in the construction industry.
In
addition, built environment professionals views varies significantly on causes
such as Lack of adequate participation of the client in the project, Changes
requested by the client, Errors in Setting out, Inadequate training and inexperience, Poor planning of
resources, Lack of protection of completed work, Excessive overtime,
Non-compliance with specification, and Damage due to weather conditions.
Based
on the conclusion, the study therefore, recommends the need for clarity,
effectiveness and timeliness of instruction and information among project
participants. In addition, the use of skilled and experienced professionals,
skilled supervisors and proper implementation of quality management practices
by both the design consultant and contractor throughout the project’s phases,
is necessary if rework free construction is to be achieved.
REFERENCES
ABDUL-RAHMAN, I.; MEMON, A. H.; ABD-KARIM, A. T. (2013)
Significant factors causing cost overruns in large construction projects in
Malaysia. Journal of Applied Sciences,
v. 13, n. 2, p. 286-293. Available: http://
http://docsdrive.com/pdfs/ansinet/jas/2013/286-293.pdf. Access: 7th
July, 2016. DOI: 10.3923/jas.2013.286.293
AJAYI, O.; OYEYIPO, O. (2015) Effect of rework on project
performance in building project in Nigeria. International Journal of Engineering Research & Technology (IJERT), v. 4, n. 2, p. 294-300.
ALRECK, P. L.; SETTLE, R. B. (1985) “The survey research handbook.’’ Richard D. Irwin, Inc., Homewood,
Ill.
ANIL, A.; DANIELRAJ, R. C. (2016) Analyze the causes and
minimize the occurrence of rework in construction project. International Journal of Innovative Research In Science, Engineering
& Technology, v. 5, n. 4, p. 6464-6467. Available :
https://www.ijirset.com/upload/2016/april/253_MY%20JOURNAL_M.pdf. Access : 5/01/2017. Doi:10.156 80/Ijirset.2016.0504253
BARBER, P.; GRAVES, A.; HALL, M.; SHEATH, D.; TOMKINS, C.
(2000) Quality failure costs in civil engineering projects. International Journal of Quality and
Reliability Management, v. 17, n. 4/5, p. 479–492.
CUSACK, D. (1992) Implementation of ISO 9000 in
construction. ISO 9000 Forum Symposium,
the International Group for Lean Construction. Gold Coast, Australia,
p.157-167.
DALTY, C. D.; CRAWSHAW, D. T. (1973) Working Drawings in Use, Building Research Establishment, Current
Paper CP 18/73, Watford, UK.
DAVIS, K.; LEDBETTER, W. B.; BURATTI, J. L. (1989)
Measuring design and construction quality costs. ASCE Journal of Construction Engineering and Management, v. 115, n.
3, p. 389–400.
ENSHASSI, A.; SUNDERMEIER, M.; ZEITER, M. A. (2017) Factors
Contributing to Rework and their Impact on Construction Projects Performance. International Journal of Sustainable
Construction Engineering & Technology, v. 8, n. 1, p. 12-33.
FANIRAN, O. O.; LOVE, P. E. D.; LI, H. (1999), Optimal
allocation of construction planning resources. ASCE Journal of Construction Engineering and Management, v. 125, n.
5, p. 311-319.
FELLOWS, R. R.; LIU, A. (2008) Research Methods for Construction, 3rd Edition. Wiley- Blackwell Science,
London.
GHASEMI, A.; ZAHEDIASL, S. (2012) Normality Test for
Statistical Analys is: A guide for non- statisticians. International Journal of EndocrinolMetab, v.10, n. 2, p. 486-489.
HWANG, B. G.; THOMAS, S. R.; HAAS, C. T.; CALDAS, C.
H. (2009) Measuring the Impact of Rework
on Construction Cost Performance. Journal
of Construction Engineering and Management, v. 135, n. 3, p. 187-198.
IRELAND, V. (1985) The role of managerial actions in the
cost, time and quality performance of high rise commercial projects. Construction Management and Economics,
v. 3, n. 1, p. 59-87.
JOSEPHSON, P. E.; HAMMARLUND, Y. (1999) The causes and
costs of defects in construction: A study of seven building projects. Automation in Construction, v. 8, n. 6,
p. 681–687.
JOSEPHSON, P.; LARSSON, B.; LI, H. (2002) Illustrative
benchmarking rework and rework costs in Swedish construction industry. Journal of Management Engineering, v.
18, n. 2, p. 76-83.
KREJCIE, R. V.; MORGAN, D. W. (1970) Determining Sample
Size for Research Activities. Educational
and Psychological Measurement, v. 30, p. 607-610.
LOVE, P. E. D. (2002a) Influence of project type and
procurement Method of Rework Costs in Building Construction Projects. Journal of Construction Engineering and
Management, v. 128, n. 1, p. 1-29.
LOVE, P. E. D. (2002b) Auditing the indirect consequences
of rework in construction: a case based approach. Managerial Auditing Journal, v. 17, n. 3, p.138–146.
LOVE, P. E. D.; LI, H. (2000) Quantifying the causes and
costs of rework in construction. Construction
Management and Economics, v. 18, n. 4, p. 479–490.
LOVE, P. E. D.; MANDAL, P.; LI, H. (1999a) Determining the
causal structure of rework in construction projects. Construction Management and Economics, v. 17, n. 4, p. 505–517.
LOVE, P. E. D.; EDWARDS, D. (2004a) Determinants of Rework
in Building Construction Projects.
Engineering, Construction and Architectural Management, v. 11, n. 4, p.259
-274.
LOVE, P. E. D.; SMITH, J. (2003) Benchmarking, bench-action
and bench-learning: rework mitigation in projects. ASCE Journal of Management in Engineering, v. 19, n. 4, p. 147-159.
LOVE, P. E. D.; DAVIS, P. R.; ELLIS, J. M.; CHEUNG, S. O.
(2010) Dispute causation: Identification of Pathogenic Influences. Engineering, Construction and Architectural
Management, v. 17, n. 4, p. 404-423.
LOVE, P. E. D.; HOLT, G. D.; SHEN, L. Y.; LI, H.; IRANI, Z.
(2002) Using systems dynamics to better
understand change and rework in construction project, management systems. International Journal of Project
Management, v. 20, n. 6, p. 425-436.
MAHAMID, I. (2016) Analysis of Rework in Residential
Building Projects in Palestine. Jordan
Journal of Civil Engineering, v. 10, n. 2, p. 197-208.
MAROSSZEKY, M.
(2006) Performance
Measurement and Visual
Feedback for Process Improvement.
A Special Invited Lecture presented in
the SMILE-SMC 3rd Dissemination Workshop. Centre for Infrastructure and
Construction Industry Development of the University of Hong Kong, Hong Kong,
2006.
MASTENBROEK, Y. C. (2010) Reducing rework costs in construction projects. Published Bsc
thesis, University of Twente, San Pedro Sula, Honduras. Available: http://purl.utwente.nl/essays/59691. Access:
10/12/2016.
MESHKSAR, S. (2012) Cost
And Time Impacts Of Reworks In Building A Reinforced Concrete Structure.
Master Thesis. North Cyprus, Gazimagusa:
Eastern Mediterranean University. Available: http://hdl.handle.net/11129/290.
Access: 10/12/2016.
MOHAMED, M. B. I. (2015) A Study Of Project Delay In Sudan Construction Industry. Published
Msc thesis, Universiti Tunku Abdul Rahman. Available:
http://eprints.utar.edu.my/1619/1/Microsoft_Word_-_A_STUDY_OF_PROJECT_DELAY_IN_SUDAN.pdf.
Access :June
1, 2017.
OMRAN A.; ABDALRAHMAN S.; PAKIR A. (2012) Project
Performance in Sudan Construction Industry: A Case Study. Academic Research Journals (India), v.1, n.1, p. 55- 78.
OYEWOBI, L.O.; OGUNSEMI, D.R., (2010) Factors influencing
rework occurrence in construction: A study of selected building projects in
Nigeria: Journal of Building Performance,
v. 1, n. 1, p. 1-20.
PALANEESWARAN, E. (2006) Reducing Rework to enhance Project
Performance Levels", Proceedings of
the one day Seminar on "Recent Developments in Project Management in
Hong Kong."
ROGGE, D. F.; CAUSES, U. o. T. A. A. C. I. I.; TEAM, E. o.
F. R. R.; UNIVERSITY, O. S. (2001) An
investigation of field rework in industrial construction. Report
No.RR153-11, CII, Austin, Texas.
ROUNCE, G. (1998), Quality, waste, and cost consideration
in architectural building design management. International Journal of Project Management, v. 16, n. 2, p. 123-127.
SAIDU, I.; SHAKANTU, W. M. W. (2016c) The contributions of
Material Waste to project-cost Overrun in Abuja, Nigeria. Acta Structilia, v. 23, n. 1, p. 99-113.
SAIDU, I.; SHAKANTU, W.M.W. (2016a) A Study of the
Relationship between Material W aste and Cost Overruns in the Construction
Industry. The 9th CIDB Postgraduate
Conference Cape Town, South Africa. Emerging trends in construction
organisational practices and project-management knowledge area. Edited
Windapo, A. O., p. 124-134, Feb, 2-4, 2016.
SIMPEH, E. K. (2012) An
Analysis of the Causes and Impact of Rework in Construction Projects. A
Thesis submitted Cape Peninsula University of Technology, South Africa.
Available: http://hdl.handle.net/11189/1054.
Access: 10/12/2016.
SMALLWOOD, J. J. (2000) A study of the relationship between occupational health and safety,
labour productivity and quality in the South African construction industry.
Published PhD (Construction Management) thesis, University of Port Elizabeth,
Port Elizabeth. Available: http://hdl.handle.net/20.500.11892/155953. Access:
1/12/2016.
SPACEY, J. (2016) What
is a Risk Trigger? Available: http://simplicable.com/new/risk-trigger,
Access: 8th March, 2017.
The NEA Research Bulletin (1960) Small-Sample Techniques. v. 38, p. 99.
THODE, H.C. (2002) Testing
for Normality. Marcel Dekker, New York. Available: http://dx.doi.org/10.1201/9780203910894.
WALKER, D. H. T. (1994) An investigation into the factors that determine building construction
time performance. PhD thesis, Department of-Building and Construction
Economics, Faculty of Environmental Design and Construction, Royal Melbourne
Institute of Technology, Melbourne, Australia. Available: http://dx.doi.org/10.1080/01446199500000030.
Access: 7th October, 2016.
WASFY. M. A. F. (2010) Severity
and impact of reworking, a case study of a residential commercial tower project
in the Eastern Province-KSA. Master Thesis. Dhahran, Saudi Arabia: King
Fahd University of Petroleum & Minerals, p.1-122.