Construction Delay: A Quantitative Analysis

Construction delay: a quantitative analysis
Ayman H. Al-Momani
Mu'tah University, Civil Engineering Department, Karak, Mu'tah, P.O. Box 7, Jordan
Abstract
Avoiding construction claims and disputes requires an understanding of the contractual terms and causes of claims. The dual
underlying theme of this paper is to investigate the causes of delays on 130 public projects in Jordan and to aid construction
managers in establishing adequate evaluation prior to the contract award using quantitative data. Projects investigated in this
study included residential, oÅce and administration buildings, school buildings, medical centers and communication facilities.
Results of this study indicates the main causes of delay in construction of public projects relate to designers, user changes,
weather, site conditions, late deliveries, economic conditions and increase in quantity. The presence of these factors have an
impact on the successful completion of the projects at the time contractually speciÆed. The Ændings suggest that special attention
to factors identiÆed in this study will help industry practitioners in minimising the risk of contract disputes. # 1999 Elsevier
Science Ltd and IPMA. All rights reserved.
Keywords: Construction management; Project planning; Construction delay; Dispute
1. Introduction
A vital section speciÆed in the construction contract
is the performance period or time of project execution,
which is established prior to bidding. The successful
execution of construction projects and keeping them
within estimated cost and the prescribed schedules
depend on a methodology that requires sound engin-
eering judgment.[1] The construction sector is one of
the vital sectors in the development process of Jordan.
The government contributes to the development of the
construction industry in several ways. However, there
are limitations and even draw backs to these e€orts.
The time required to complete construction of public
projects is frequently greater than the time speciÆed in
the contract. These `overruns' or time extensions are
granted for many reasons, such as designer changes or
errors, user changes, weather and late deliveries.
Current construction projects are complex e€orts
requiring the support of the design and construction
profession. Therefore, a realistic time for project ex-
ecution will decrease the possibility of disputes
between state agency and the contractors.
1.1. Previous work
A great deal of information concerned with project
delay and overruns may be found in the literature. The
increased interest in construction overruns is due, in
part, to e€orts by the government to reduce construc-
tion delays. There has been a considerable and contin-
ued interest in the e€ect of construction delays. The
information available is diverse and widespread. Many
construction management books[2±6] have minimum
coverage on construction delays. Al-Momani[7]
describe the various elements of cost upon individual
public projects but does not deal speciÆcally with con-
struction delays.
Assaf and Al-khalil[8] outline the main causes of
delay in large building projects and their relative im-
portance. They found that 56 causes of delay exist in
Saudi construction projects. According to the contrac-
tors surveyed the most important delay factors were
preparation and approval of shop drawings, delays in
contractor's progress, payment by owners and design
changes. The architects and engineers view were cash
problems during construction, the relationship between
subcontractors and the slow decision making process
International Journal of Project Management 18 (2000) 51±59
0263-7863/99/$20.00 # 1999 Elsevier Science Ltd and IPMA. All rights reserved.
PII: S 0 2 6 3 - 7 8 6 3 ( 9 8 ) 0 0 0 6 0 - X
www.elsevier.com/locate/ijproman

of the owner. The owners agree that the design errors,
labor shortages and inadequate labor skills are import-
ant delay factors. Hancher and Rowings,[1] for example,
provide a concise summary of the methodologies used
by transportation agencies to establish the contract dur-
ation used for highway construction projects, and also
provides a schedule guide for Æeld engineers during con-
struction. Similarly, Chalabi and Camp[10] conducted a
review on project delays in developing countries during
planning and construction stages. In their study they
found that the delay and cost overruns of construction
projects are dependent entirely on the very early stages
of the project. Fereig and Qaddumi[11] in their study on
the construction experience of the Arabian Gulf demon-
strate the various components of the planning, control-
ling and productivity on construction delay. Their
primary purpose is to alert the reader to the deviation
from the project plans.
Wilson[9] examined the role of the owner and archi-
tect/engineer's roles in the prevention and resolution of
construction claims. Wilson also summarised the
causes of construction claims which include: extra
work, project delays and acceleration, lack of manage-
ment, limited site access and change in work schedule.
Despite the necessity for such research, little work
has been described in the literature concerning public
projects, specially in Jordan. The previously proposed
factors contributing to construction delay were fre-
quently observed in public projects. The actual fre-
quency and magnitude of these factors is not known,
which has proven to be a serious and very expensive
problem to Jordan's construction industry.
1.2. Research design and objectives
The objective of this study is to determine the causes
and the level of time extension of public projects and
to aid construction managers in establishing adequate
evaluation prior to the contract award using quantitat-
ive data. The key task is to design research so that the
information obtained permits the assessment of their
impact. Therefore, the best approach to assessing these
potentials is to adopt randomly selected samples. The
sampling population was established by selecting 130
public projects constructed in di€erent regions of
Jordan during the period of 1990±97. The data was
found in contract Æles of several state agencies. Data
collected were of 5 kinds of public projects: residential
houses of public Ægures, oÅce and administrative
buildings, school buildings, medical centers and com-
munication facilities. The performance and construc-
tion of these projects were recognised as being
unsatisfactory to many oÅcials, and assented to the
study in order to have hard evidence as to the nature
of the problems. This study will summarise the results
of this research based on actual construction times ex-
perienced by public projects. The data collection was
to investigate the reasons related to construction delay
and overruns:
. Planned duration of contract;
. Actual completion date;
Table 1
Summary of project information
ClassiÆcation Poor
design
Change
orders
Weather Site
condition
Late
delivery
Economic
condition
Increase in
quantity
No
delay
Total
House 4 1 3 1 0 0 2 3 14
OÅce 8 5 4 2 1 4 5 5 34
School 10 8 6 5 4 2 3 14 52
Medical centers 6 4 2 0 3 2 1 2 20
Communication facilities 4 2 1 0 2 0 1 0 10
Total 32 20 16 8 10 8 12 24 130
Table 2
Descriptive statistics of the public projects
Number of Duration
Project categories projects
Planned Actual
House 14
max. 450 832
min. 75 66
mean 221.4 297.2
SD 102.3 192.9
OÅce and administrative buildings 34 max. 750 751
min. 100 67
mean 354.6 442.2
SD 120.0 152.9
School buildings 52 max. 660 928
min. 150 225
mean 395.4 467.5
SD 129.7 141.1
Medical centers 20 max. 720 904
min. 90 193
mean 313.5 444.5
SD 162.6 231.7
Communication facilities 12 max. 360 410
min. 195 230
mean 268.2 308.2
SD 58.0 59.9
A.H. Al-Momani / International Journal of Project Management 18 (2000) 51±5952

Fig. 1. Causes of delay.
A.H. Al-Momani / International Journal of Project Management 18 (2000) 51±59 53