The problem of disputes in the construction industry is a global phenomenon and the costs associated with resolving disputes are significant. According to Love et al. (2010) direct costs associated with disputes range from 0.5 to 5 percent of project's contract value. The indirect costs, on the other hand, resulting from lost productivity, stress, fatigue, loss of future work, the cost of strained business relationships among the various parties and tarnished reputation may cause even more damage to the project and parties involved. Given their importance, prevention of disputes becomes one of the most important processes that determine the performance of a construction project and it depends highly on a sound understanding of dispute occurrence.
Despite a number of dispute occurrence related studies in the past, there is still a lack of empirical research carried out on the associations between dispute factors and dispute categories. In this context, the main purpose of this study is to:
distinguish dispute factors from dispute categories, terms generally used interchangeably in the literature;
compose consistent and comprehensive lists of dispute factors and categories; and
identify the impacts of various dispute factors through empirical analysis of the associations between dispute factors and categories.Earlier studies considered either the factors or the categories of disputes separately, and mainly focused on determining their frequencies. This study takes an integrated approach and attempts to analyse the impact of specific factors on specific categories because it is believed that identification of factors or categories alone does not help the practitioners to take appropriate preventive steps. This paper aims to provide suggestions for all stakeholders and attempt to show which factors result in which dispute situations. Once these associations become clear, practitioners can take proactive steps to avoid such situations.
2 Previous studies on dispute occurrence
Considerable amount of research has been done on dispute occurrence and the literature offers much theorizing about the causes of disputes. Fenn et al. (1997) , however, previously suggested that there had been limited empirical evidence to justify the theories that have been presented in the disputes literature. According to Love et al. (2010) , Fenn et al.'s (1997) observation is still pertinent some ten years on and while the accumulated knowledge about dispute occurrence has been able to provide the initial building blocks for understanding the underlying pathogens contributing to disputes, more empirical research is required to explain the actual impacts of these pathogens.
Table I shows a synopsis of dispute occurrence in literature. A survey of this table reveals that there is a certain level of commonality in the patterns that lead to disputes in different contractual regimes, as Kumaraswamy (1998) also drew attention to more than a decade ago. On the other hand, it is also possible to see that the lists compiled by the authors have a degree of diversity regarding the level of detailing the factors. While Diekman and Girard (1995) provided much less detail in their lists of factors and suggested “product, process and people” as the root causes of disputes similarly to Sykes (1996) who suggested “misunderstandings and unpredictability” as the causes of disputes, others tackled dispute causation on a more detailed level. For instance, Kumaraswamy (1997) diversified solely “variations” into three categories as “variations due to site conditions, variations due to client changes, and variations due to design errors”.
There is also diversity in the methodological approaches of the studies listed. While a greater portion is based on the analysis of judgements from litigation cases and dispute records in various databases, few are based on actual projects. These studies mainly focus on determining the frequencies of the occurrence of factors that were previously decided to occasion the development of a dispute and while they provide us information regarding which factors are observed more frequently than others in the construction projects, we still do not know much about the associations in disputes, such as the correlations of certain factors with certain categories of disputes.
Differentiating between dispute factors and dispute categories
The literature on dispute occurrence also demonstrates a problem of terminology. Analysing Table I, one can see the required differentiation between the concepts that cause disputes and the ones that actually depict the nature of a dispute. Although they constitute two distinct notional domains with a clear need of demarcation, the difference between the causes and the categories of disputes is often unclear and terms such as “pathogens”, “causes”, “root causes”, “factors”, “situations”, “categories”, “areas”, “groupings” and “types” have been used interchangeably to describe these concepts (Table I). For instance, while “variations” was characterized as a “source of dispute” by Yiu and Cheung (2007) and as a “cause of dispute” by Ashworth (2005) and Adriaanse (2005) , it was characterized as a “problem area of dispute” by Chan and Suen (2005) and a “dispute category” by Kumaraswamy (1997) . Similarly “delays” was characterized as a “source of dispute” by Yiu and Cheung (2007) and as a “cause of dispute” by Ashworth (2005) and Adriaanse (2005) , but it was characterized as a “key dispute area” by Conlin et al. (1996) . As for “payments”; it was characterised as a “root cause” by Cheung and Yiu (2006) , as a “problem area of dispute” by Chan and Suen (2005) , as a “cause of dispute” by Ashworth (2005) and as a “key dispute area” by Conlin et al. (1996) . “Poor communication” was characterized as a “root cause” by Cheung and Yiu (2006) , as a “cause” by Ashworth (2005) and Kumaraswamy (1997) , as a “primary cause” by Bristow and Vasilopoulous (1995) and as a “factor” by Rhys-Jones (1994) , but it was characterized as a “problem area of dispute” by Chan and Suen (2005) . “Contracts” was characterized as a “root cause” by Cheung and Yiu (2006) , as a “cause of dispute” by Ashworth (2005) and Adriaanse, as a “primary cause” by Bristow and Vasilopoulous (1995) , as a “factor” by Rhys-Jones (1994) and Mitropoulos and Howell (2001) but as a “problem area of dispute” by Chan and Suen (2005) and a “dispute category” by Kumaraswamy (1997) . This list can be extended, however given examples are enough to demonstrate that current literature on dispute occurrence makes it difficult to determine which of the listed factors give rise to a dispute and which are actually the different types of disputes, themselves. While Kumaraswamy (1997) and Semple et al. (1994) attempted to differentiate between causes and categories of disputes in their research, the provided lists fail to be comprehensive compared to the lists proposed by some other authors, not consistent regarding the chosen level of detailing and include some overlaps, hence the need for a more clear and systematic approach.
In this context, this paper attempts to determine which concepts listed by the authors actually give rise to a dispute and which are themselves different types of disputes and suggests classifying the dispute occurrence concepts into “dispute factors” and “dispute categories”. It is believed that this differentiation is crucially instrumental not only in helping avoid problems in terminology but more importantly in facilitating an enhanced conceptualization and understanding of dispute occurrence, itself. It is only after this classification, that determination of correspondence and empirical correlations between dispute factors, dispute frequency and dispute categories become possible. The need for empirical research in the area of disputes was pointed out by many authors before ( Love et al., 2010 ; Fenn et al., 1997 ).
Table II shows the...
