Causes of Delays in Portuguese Construction Projects

Amílcar Arantes

and Luis Miguel D. F. Ferreira

CESUR, Instituto Superior Técnico, Universidade Lisboa, Av. Rovisco Pais, Lisboa, 1049-001, Portugal

Economics, Management and Industrial Engineering Department, University of Aveiro, Aveiro, 3810-193, Portugal

Keyword: Construction Delays, Construction Industry, Portuguese Construction Industry, Project Management,

Relative Importance Index, Factor Analysis.

Abstract: Delays are frequent in engineering and construction projects all over the world. Delays can have severe

impacts, such as time and cost overruns and conflicts between stakeholders, and can also lead to total

abandonment of the contract. This paper presents the findings of a survey conducted to identify the most

important causes of delays in the Portuguese construction industry. Among the respondents were

representatives from all stakeholders involved: contractors, consultants and developers. The Relative

Importance Index was adopted to classify the relative importance of the 46 identified causes of the delays.

The results show that the main causes of delay were slow decision making by developers, change orders,

unrealistic contract duration and specifications in contracts, financial constraints on the contractor and the

type of bidding and award of contract process. Additionally, factor analysis revealed eight high-level causes

that aggregate 30 of the original causes. These findings are expected to contribute to expanding the

knowledge in the scientific community of construction management, in particular in the field of supply

chain management, and helping the Portuguese industry in the reduction and prevention of delays in

construction projects.

1 INTRODUCTION

Delays in construction projects have always been a

global issue regardless of the type of project. In

construction, a delay can be defined as the time

overrun either beyond the completion date specified

in the respective contract, or beyond the date the

contract parties agree upon for delivery of a project

(Assaf and Al-Hejji, 2006).

The construction process is usually divided into

3 distinct phases: planning, design and construction,

and it is in this last phase, which involves many

unpredictable factors, that most delays usually occur

(Chan and Kumaraswamy, 1997). Time performance

is one of the basic parameters for evaluating the

success of a construction project and must always be

one of the main concerns in project management. A

project is considered successful if it meets the

requirements of 3 major indicators: time, cost and

quality. Rwelamila and Hall (1995) also found that

the timely completion of a project was frequently

seen as one of the major parameters for evaluating

project success. With this in mind, it is no surprise

that project duration is a decisive criterion for

developers when choosing a contract.

When a project faces delays it is usually extended or

accelerated and both solutions have additional costs

implied. Project delays are so frequent that it is

common practice for a contingency cost to be

included in the contract, which is normally a

percentage of the total contract price, to cover cases

of delay (Chan and Kumaraswamy, 1997). A range

of problems can arise as a consequence of delays,

particularly problems of a financial nature, which

often result in conflicts between the stakeholders

involved: contractors, consultants and developers.

Despite all the efforts to prevent delays, the

complexity of project design and construction makes

it often difficult to identify the causes of the delays.

Precisely identifying the causes may be even more

difficult because many of them are often

interconnected (Alkass et al., 1996), meaning that

delays can be a consequence of each another.

In Portugal the scenario is no different and

delays affect a large percentage of construction

projects. However, in recent years, the financial

crisis has led to a major stagnation in

the

construction industry, forcing several companies to

declare bankruptcy or move abroad. With all the

resulting financial constraints, the market is

116

Arantes A. and Miguel D. F. Ferreira L..

Causes of Delays in Portuguese Construction Projects.

DOI: 10.5220/0005214501160124

In Proceedings of the International Conference on Operations Research and Enterprise Systems (ICORES-2015), pages 116-124

ISBN: 978-989-758-075-8

 2015 SCITEPRESS (Science and Technology Publications, Lda.)

becoming increasingly more competitive and

optimizing the cost and time factors has become

essential for contractors. Accordingly, identifying

the causes of delays is a key factor for process

optimization.

A number of papers have been produced over the

last two decades in relation to this matter but most of

them have been far from the Portuguese context. The

aim of this research work is, thus, to identify the

main causes of delays in the Portuguese construction

industry and understand the links between them. It is

also important to understand the differences of

opinion between the various stakeholders involved

in construction projects.

2 LITERATURE REVIEW

Many researchers have studied the causes and

effects of delays in the construction industry in

recent decades. Mansfield et al. (1994) identified 16

major causes of delays and cost overruns in Nigerian

construction projects by means of a questionnaire

survey that was conducted with contractors,

consultants and developers. They concluded that the

main causes of delays and time overruns had to do

with finance and payment arrangements, poor

contract management, shortage in materials,

inaccurate estimates and price fluctuations.

Ogunlana et al. (1996) conducted a study on

causes of delays in Thailand, analyzing 12

skyscraper projects in Bangkok. They identified 26

causes of delays and concluded that material

shortages, especially cement, lack of qualified

workforce, change orders by the developers and

inadequate contractor experience were the most

important ones.

Chan and Kumaraswamy (1997) conducted

survey-based research in Hong Kong with

contractors, consultants and developers with a view

to classifying the relative importance of 83 causes of

delays. They concluded that the main causes of

delay were poor site management and supervision,

unforeseen ground conditions, low speed of decision

making involving all project teams, developer

initiated variations and necessary variations of work.

Odeh and Battaineh (2002) conducted survey-

based research in Jordan to identify the main causes

of delays in traditional construction projects.

Contractors and consultants were asked to complete

a questionnaire to evaluate the relative importance of

28 pre-selected causes. They concluded that the

major causes of delays were inadequate contractor

experience, developer interference, delay in progress

payments by the developer, slow decision making by

the developer, improper planning, low productivity

level of labour and problems with subcontractors.

Doloi, Sawhney, Iyer, and Rentala (2012)

conducted a survey to identify the main causes of

delays in different types of construction projects in

India. They selected a group of 45 causes and

classified them according to the respondents’

answers. The most important causes of delays

indicated by the respondents were delays in material

delivery by vendors, non-availability of drawings on

time, financial constraints on the contractor,

increases in scope of work and obtaining

permissions from local authorities. Using factor

analysis, they identified lack of commitment,

inefﬁcient site management, poor site coordination

and improper planning as the most critical

(extracted) factors in construction delays.

Gündüz, Nielsen and Özdemir (2012)

conducted a survey to determine the relative

importance of 83 different causes of delays in the

Turkish construction industry. They surveyed 64

specialists in the field and concluded that inadequate

contractor experience, ineffective project planning

and scheduling, poor site management and

supervision, design changes by the developer and

late delivery of materials were the most important

causes of delays.

Fallahnejad (2013) carried out a study on causes

of delays analyzing 24 gas pipeline projects in Iran.

He used a questionnaire to evaluate the relative

importance of 43 different causes, concluding that

the main causes of delays were inability on the part

of contractors to provide imported materials,

unrealistic contract durations imposed by the

developer, slow delivery of materials by the

developer, slow land expropriation due to resistance

from occupants and change orders by developers.

It is clear from the studies in the literature

reviewed that the causes and effects of delays in

construction depend on the type of construction

project and on the country where the project is

undertaken. Some of the authors also recommended

that similar studies should be conducted in other

countries and types of construction projects (Assaf

and Al-Hejji, 2006; Sambasivan and Soon, 2007).

Accordingly, the study presented herein contributes

to expanding knowledge on causes and effects of

delays in construction projects, in particular in

Portugal.

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3 RESEARCH METHODOLOGY

For this research project a questionnaire survey

methodology was used to determine the importance

of the causes of delays in the construction industry.

Major progress has been made in investigations

based on survey research methodology in recent

years (Vickery, 1998). Several authors have used

survey research methodology in similar studies

(Chan and Kumaraswamy, 1997; Doloi et al., 2012;

Gündüz et al., 2012; Manavazhi and Adhikari, 2002;

Mansfield et al., 1994; Odeh and Battaineh, 2002;

Sambasivan and Soon, 2007).

Questionnaire design is a key part of survey

research methodology. It is important that the

questionnaire is clear and has no mistakes or

discrepancies in its design. To accomplish this, basic

ground rules for social surveys were adopted in

questionnaire design (Fowler, 2009). The

questionnaire was developed to assess the

importance of the causes of delays. To this end a

five point Likert scale was adopted (1 - very low; 2 -

low; 3 - average; 4 - high; 5 - very high).

After a meeting with experts from the Portuguese

construction industry, a total of 47 causes of delays

reported in the literature were considered enough to

capture the Portuguese reality and were include in

this research. These causes were divided into 9

categories, namely: developer-related causes,

contractor-related causes, consultant-related causes,

material-related causes, Labour and equipment-

related causes, design-related causes, contract and

contractual relationships-related causes, external

causes and authority-related causes.

After the questionnaire design was concluded a

pilot test was carried out with a limited number of

companies to check the effectiveness in collecting

information and to identify possible mistakes or

misunderstandings. After this pilot test some

changes were made in the questionnaire. The

questionnaire was then distributed by electronic mail

to a selected sample of 150 contractors, 100

consultants and 70 developers.

Sample selection plays a decisive role in survey

research methodology and mistakes in this process

will reduce confidence in the results. Furthermore,

non-respondents can alter a sample frame and lead

to non-response bias, which can compromise the

validity of the results. To avoid these issues, all

recommendations by Forza (2002) regarding sample

size and design and non-response bias were taken

into consideration. Of the 320 questionnaires sent

out, 139 were returned: by 62 contractors, 46

consultants and 31 developers. With the responses

obtained from the survey, the data was then analysed

using statistical tools.

4 RESULTS

4.1 Ranking of Causes

The Relative Importance Index (RII) method was

adopted in this study to evaluate the relative

importance of causes of delay. This methodology is

common in survey research and has been used by

several authors (Aibinu and Jagboro, 2002; Assaf,

Al-Khalil and Al-Hazmi, 1995; Chan and

Kumaraswamy, 1997; Doloi et al., 2012; Frimpong,

Oluwoye and Crawford, 2003; Gündüz et al., 2012;

Odeh and Battaineh, 2002; Sambasivan and Soon,

2007). For each cause the respective RII is

calculated as in Eq. (1):

RII =

∑

WAN

⁄

(1)

Where

W - Importance given to each cause (1 to 5)

A - Highest weight (A = 5)

N - Total number of respondents

The ranking of causes is presented in table 1. The

most important cause, in the opinion of the

respondents, was “slow decision making by the

developer”. Timing of decision-making is crucial in

construction projects and delays in this process can

halt the work progress. The following causes in the

top 5, again according to the respondents, were:

“change orders”, “unrealistic time schedule and

specifications in contract”, “financial constraints on

the contractor” and “type of bidding and contract

award process”. Respondents also indicated “delay

in progress payments by owner”, “improper

planning and scheduling”, “developer interference,

“increase in scope of work” and “mistakes and

discrepancies in drawings” as important causes of

delay. Along with this ranking, it is important to

identify the differences of opinion between the

various types of respondents. Contractors indicated

“slow decision making by the developer” as the

major cause of delays. Consultants identified

“unrealistic time schedule and specifications in

contract” as the most important causes of delay,

while developers indicated “financial constraints on

the contractor” as the major cause.

For a better comparison between the respondent

types, table 2 presents the ranking of categories of

causes according to each type and the global

ranking. “developer”-related causes and “contract

and contractual relationships”-related causes are the

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Table 1: Ranking of causes of delay.

Causes of delay RII Rank Causes of delay RII Rank

Developer-related causes

Material-related causes (cont.)

C1 - Delay in progress payments by

developer

0.770 6

C26 - Changes in material specifications

during construction

0.717 13

C2 - Slow decision making by developer 0.849 1 C27 - Delay in materials procurement 0.721 12

C3 - Developer interference 0.736 8 C28 - Change in material prices 0.523 43

C4 - Delay in handing over the site to

contractor by developer

0.574 38 Labour and equipment-related causes

C5 - Increase in scope of work 0.732 9 C29 - Lack of qualified Labour 0.626 30

C6 - Change orders 0.845 2 C30 - Low Labour productivity 0.651 27

C7 - Bureaucracy in developer’s

organization

0.670 22 C31 - Equipment availability and failure 0.574 38

Contractor-related causes C32 - Inadequate equipment 0.596 34

C8 - Delays and changes of

subcontractors

0.655 26 Design-related causes

C9 - Inadequate construction methods 0.626 30

C33 - Mistakes and discrepancies in

drawings

0.728 10

C10 - Improper planning and scheduling 0.755 7 C34 - High complexity of drawings 0.587 35

C11 - Mistakes during construction 0.645 28

C35 - Delay in producing design

documents

0.632 29

C12 - Inadequate contractor experience 0.677 18 Contract and contractual relationship causes

C13 - Site accidents 0.474 47

C36 - Bidding and contract award

process

0.828 5

C14 - Poor site management and

supervision by contractor

0.577 37

C37 - Unrealistic time schedule and

specifications in contract

0.845 3

C15 - Financial constraints on part of

contractor

0.843 4

C38 - Mistakes and discrepancies in

contract

0.666 24

C16 - Delay in site mobilization by

contractor

0.657 25

C39 - Lack of motivation for contractor

to finish early

0.560 41

Consultant-related causes

C40 - Lack of communication between

parties

0.696 16

C17 - Inflexibility of consultant 0.668 23

C41 - Disputes and negotiations between

parties

0.711 14

C18 - Delay in approval of drawings 0.674 20 External causes

C19 - Delay in quality control 0.621 32 C42 - Unforeseen site conditions 0.687 17

C20 - Lack of control over subcontractor 0.521 44 C43 - Problems with neighbours 0.566 40

C21 - Waiting time for approval of tests

and inspections

0.598 33 C44 - Unavailability of utilities in site 0.511 45

Material-related causes C45 - Weather conditions 0.672 21

C22 - Inadequate material quality 0.585 36 Authority-related causes

C23 - Damaged materials 0.511 45 C46 - Changes in government regulations 0.530 42

C24 - Shortage in materials 0.677 19

C47 - Delay in obtaining permits from

authorities

0.726 11

C25 - Delay in material delivery 0.711 14

most important categories of causes of delays. The

major difference in the responses from the different

types of respondents is in the importance given to

“contractor”-related causes; consultants and

developers agree as to the decisive importance of

this category but contractors attach more importance

to “design”-related causes and “consultant”-related

causes. The main conclusion is that consultants and

developers agree more with each other than with

contractors. Since data was collected based on a

Likert-scale, it can be considered as interval data,

correlation analysis is an effective method to study

relationships between these types of variables

(Sekaran and Bougie, 2010). Therefore, the same

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119

conclusion can be inferred analyzing the Spearman’s

rank of correlation (Assaf and Al-Hejji, 2006),

presented in table3, which tests the degree of

agreement between respondent types with a

statistical significance of 0.001. One can also

conclude that the most significant differences in

opinions are between contractors and developers.

4.2 Factor Analysis

Factor analysis is a statistical tool that reveals

correlations between variables that do not appear to

be related and groups them into a much smaller

number of underlying factors (Doloi, 2009). Factor

analysis was useful in this study to identify

correlations between causes of delay that didn’t

seem related at first, and it has been used before in

similar studies (Doloi et al., 2012). To evaluate the

adequacy of the survey results for factor analysis,

the KMO and Bartlett’s test of sphericity were

conducted (Field, 2013).The result of KMO value

was 0.748, which is higher than 0.5, the minimum

value suggested by Kaiser (1974). Eight factors were

extracted representing 30 causes of delay; 17 causes

of delay were found to have no significant

correlation with another one. These eight factors

explained approximately 70% of total variance and

are presented in table 4. The factor analysis was

carried out using principal components analysis of

the statistical package for social sciences (SPSS).

To validate that extracted factors measure what

they are intended to, it is necessary to cross check if

the causes within each factor are related to each

other (Doloi, 2009). To measure the degree of

correlation between causes of delays in each factor,

the Pearson correlation coefficient was calculated

and presented in tables 5 to 12. For coefficient

values greater than 0.7 correlation is deemed to be

strong and for coefficient values between 0.3 and 0.7

correlation is considered moderate. All correlation

coefficients between causes present values higher

than 0.3, so one can conclude that the factors

extracted from factor analysis contain related causes.

Along with this correlation analysis it is also

necessary to conduct a reliability analysis to ensure

the consistency of measured causes and its scale

(Doloi et al., 2012). To this end, Cronbach’s alpha

test was carried out on the causes of delays of each

factor and on all 30 causes of delays extracted from

the factor analysis. The results of this test are

presented in tables 5 to 12. Although there is no

established minimum for an acceptable value of

Cronbach’s alpha (Cα), Doloi (2009) suggests the

following scale: Cα > 0.9 - excellent; 0.9 > Cα > 0.8

- good; 0.8 > Cα > 0.7 - acceptable; 0.7 > Cα > 0.6 -

questionable; 0.6 > Cα > 0.5 - poor and 0.5 > Cα -

unacceptable. All Cronbach’s alpha values are

greater than 0.6 and overall result is 0.917 which is

considered excellent. Therefore, all results of the

factor analysis can be accepted and have statistical

meaning.

Table 3: Spearman's rank of correlation coefficients

categories.

Entity Contractor Consultant

Developer

Contractor 1

Consultant 0.727 1

Developer

0.648 0.831 1

The first factor (inefficient site management)

contains 6 causes of delays all of them directly

related to inefficient site management by the

contractor: delays and changes of subcontractors,

Table 2: Ranking of cause of delay categories.

Category

Respondents

Contractor Consultant

Developer

Global

RII Rank RII Rank RII Rank RII Rank

Developer

0.764 1 0.701 2 0.727 1 0.74 1

Contract and contractual relationships 0.723 2 0.704 1 0.724 2 0.717 2

Contractor 0.664 6 0.623 3 0.711 3 0.657 3

Design 0.693 3 0.576 6 0.636 5 0.649 4

Material 0.647 8 0.588 4 0.704 4 0.635 5

Authority 0.668 5 0.557 7 0.627 6 0.628 6

Consultant 0.685 4 0.509 9 0.578 9 0.617 7

Labour and equipment 0.633 9 0.582 5 0.591 7 0.612 8

External causes 0.659 7 0.53 8 0.582 8 0.609 9

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inadequate construction methods, improper planning

and scheduling, mistakes during construction,

inadequate contractor experience and poor site

management and supervision by contractor. The

contractor plays a decisive role in construction

projects and the quality of its performance is crucial

to avoid delays. If the contractor is not committed to

finishing the project on time than its performance

will be poor and delays will occur frequently.

Contractor performance and commitment brings

together all these causes of delay into one unique

factor and it is easy to understand the correlation

between them.

The second factor (lack of productivity) groups 5

causes of delays related with materials, labour and

equipment: shortages in materials, delay in materials

delivery, low labour productivity, equipment

unavailability and failure and inadequate equipment.

Unavailability of equipment or inadequate

equipment can significantly decrease labour

productivity and it is a clear sign of improper

planning and poor site management. In addition,

shortage in material, which can be a consequence of

delays in materials delivery or improper planning,

also leads to a decrease in labour productivity. Low

labour productivity combined with work stoppages

due to shortages of materials or equipment failure

can also be considered a major reason for

construction delays.

The third factor (poor control) links 4 causes of

delay, all of them related to poor control by the

consultant: inflexibility of consultant, delay in

approval of drawings, delay in quality control and

waiting time for approval of tests and inspections.

Consultants also play an important role in

construction projects and rigidity and inflexibility on

their part can cause significant delays in work

progress. Consultants have to ensure the quality of

the contractor’s performance and have the power to

stop the work progress to perform tests and

inspections. Therefore, if a consultant takes too long

on this process or is inflexible on its demands,

delays can occur and work schedules can be

compromised.

The fourth factor (lack of commitment)

associates 4 causes of delay related with various

categories: lack of control over subcontractor,

inadequate quality of materials, change in materials’

prices and lack of motivation for contractor to finish

early. Although these causes of delays may seem

unrelated, their correlation relies mostly on the

subcontractor’s commitment. Lack of motivation on

the part of the contractor means that it is sloppier in

the process of choosing and controlling the

subcontractors, making it harder for the consultants

to control and monitor all of them. Because of this,

subcontractors feel free to lower the quality of

materials and change their prices in order to increase

their profits.

The fifth factor (lack of communication) groups

together 3 causes of delays related with the contract

and contractual relationships: unrealistic time

schedule and specifications in contract, lack of

communication between parties and disputes and

negotiations between parties. In order to be

competitive, contractors reduce time schedules

beyond reasonable terms and then are unable to meet

their initial proposal. This issue immediately

originates time overruns and frequently leads to

disputes between parties that slow down or stop

work progress. In addition to this, lack of

communication between all parties involved also

leads to disputes and negotiations.

The sixth factor (interference of the developer)

links 3 developer-related causes of delays: slow

decision making by the developer, developer

interference and change orders. Along with the

contractor and the consultant, the developer plays a

major role in construction projects. All these causes

of delay are related to developer interference in the

process, so the correlation between them makes

sense. Slow decision making and interference can

slow down or even stop the work progress and

generate delays. Change orders by the developer

also lead to scheduling modifications that can delay

the completion of a project.

The seventh factor (financial constraints)

associates 3 causes of delays related with financial

issues: delay in progress payments by developer,

financial constraints on the contractor and the

bidding and award of contract process. These causes

of delays are directly related with the financial

problems faced by both the developer and

contractor. Delays in progress payments by the

developer force the contractor to use their own

financial resources to supply the project activities,

otherwise the work will be halted. The type of

bidding and award of contract process is also

associated with these causes due to its financial

nature. Developers frequently choose the lowest

bidder in awarding their contracts. In order to be

more competitive and offer lower prices, contractors

reduce their profit margins and become more

vulnerable to payment delays.

The eighth factor (excess of and changes in

bureaucracy) contain 2 causes of delays related with

bureaucracy: bureaucracy in the developer’s

organization and changes in government regulations.

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Table 4: Factor analysis.

Factors extracted

Factor

Factors extracted

Factor

Factor I - Inefficient site management Factor IV – Lack of commitment

C8 - Delays and changes of subcontractors 0.660 C20 - Lack of control over subcontractor 0.725

C9 - Inadequate construction methods 0.650 C22 - Inadequate material quality 0.536

C10 - Improper planning and scheduling 0.818 C28 - Change in material price 0.660

C11 - Mistakes during construction 0.753

C39 - Lack of motivation for contractor to

finish early

0.617

C12 - Inadequate contractor experience 0.652 Factor V - Lack of communication

C14 - Poor site management and supervision by

contractor

0.710

C37 - Unrealistic time schedule and

specifications in contract

0.576

Factor II – Lack of productivity C40 - Lack of communication between parties 0.597

C24 - Shortages in materials 0.592 C41 - Disputes and negotiations between parties 0.770

C25 - Delay in materials delivery 0.596 Factor VI - Related to developer

C30 - Low labour productivity 0.624 C2 - Slow decision making by developer 0.833

C31 - Equipment unavailability and failure 0.714 C3 - Developer interference 0.794

C32 - Inadequate equipment 0.737 C6 - Change orders 0.546

Factor III – Poor control Factor VII - Financial constrains

C17 - Inflexibility of consultant 0.717 C1- Delay in progress payments by owner 0.689

C18 - Delay in approval of drawings 0.802 C15 - Financial constraints on contractor 0.567

C19 - Delay in quality control 0.762 C36 - Bidding and award of contract process 0.624

C21 - Waiting time for approval of tests and

inspections

0.756 Factor VIII – Excess of and changes in Bureaucracy

C7 - Bureaucracy in developer’s organization 0.736

C46 - Changes in government regulations 0.610

Table 5: Pearson correlation between causes for factor I

=0.867).

C8 C9 C10 C11 C12 C14

C8 1

C9 0.508 1

C10 0.582 0.541 1

C11 0.553 0.540 0.647 1

C12 0.376 0.364 0.554 0.632 1

C14 0.359 0.580 0.514 0.484 0.587 1

Table 6: Pearson correlation between causes for factor II

=0.885).

C24 C25 C30 C31 C32

C24 1

C25 0.789 1

C30 0.509 0.575 1

C31 0.441 0.531 0.664 1

C32 0.577 0.545 0.713 0.763 1

Table 7: Pearson correlation between causes for factor III

=0.873).

C17 C18 C19 C21

C17 1

C18 0.703 1

C19 0.570 0.646 1

C21 0.609 0.616 0.651 1

Table 8: Pearson correlation between causes for factor IV

=0.750).

C20 C22 C28 C39

C20 1

C22 0.648 1

C28 0.476 0.371 1

C39 0.386 0.327 0.389 1

Both these causes are related to the formal

requirements demanded by the developer and the

legislation. Excessive bureaucracy in the developer’s

organization can delay the work progress in many

ways. The most common types of bureaucracy are

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excessive paper work and inefficient communication

chains. Changes in legislation are also a major

problem in construction projects, on account to their

external nature and unpredictability.

Table 9: Pearson correlation between causes for factor V

=0.712).

C37 C40 C41

C37 1

C40 0.301 1

C41 0.416 0.634 1

Table 10: Pearson correlation between causes for factor VI

=0.703).

C2 C3 C6

C2 1

C3 0.531 1

C6 0.361 0.440 1

Table 11: Pearson correlation between causes for factor

VII (C

=0.651).

C1 C15 C36

C1 1

C15 0.486 1

C36 0.300 0.391 1

Table 12: Pearson correlation between causes for factor

VIII (C

=0.670).

C7 C46

C7 1

C46 0.509 1

Finally, from the seven factors extracted in this

study, only 3 can be found in the work of Doloy et

al. (2012), (ie, lack of communication, lack of

commitment and inefficient local management),

reflecting the differences between the contexts.

5 CONCLUSIONS

Based on this research work, one can conclude that

slow decision making by the developer is the major

cause of delays in construction projects in Portugal.

Change orders, unrealistic time schedule and

specifications in contract, financial constraints on

the contractor, the bidding and award of contract

process and delay in progress payments by the

developer are also important causes. Another

conclusion is that consultants and developers have

similar opinions and both of them disagree in certain

matters with the contractor. Developer-related

causes, contract and contractual relationships-related

causes and contractor-related causes are the most

important categories of causes of delays.

Using factor analysis it was possible to connect

and group several causes of delays into eight major

factors that are responsible for delays in Portuguese

construction projects, namely: inefficient site

management; lack of productivity; poor control; lack

of commitment; lack of communication; developer

interference; financial constraints; and excess of and

changes in bureaucracy.

This research contributes to the development and

expansion of construction management knowledge

in the scientific community, particular in the field of

project management, and helps the Portuguese

industry to prevent the causes of delays and,

accordingly, mitigate their effects.

Although the sample size is considerable (139

respondents), a greater number of respondents could

provide more information and increase the statistical

significance of the results. Moreover, the sample is

not equally distributed among the types of

respondents and, despite all the measures taken, this

could give rise to some bias in the responses. One

last limitation of this research is that the results

achieved, whilst comparable with similar published

studies, are specific to the Portuguese realty.

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