Quantification of Delay Factors Using the Relative Importance Index Method for Construction Projects in Turkey Murat Gündüz, Ph.D., A.M.ASCE 1 ; Yasemin Nielsen, Ph.D. 2 ; and Mustafa Özdemir 3 Abstract: Construction delays are common in construction industry and create major concerns for project performance. Construction delays are caused by many factors. The aim of this paper is to identify delay factors on construction projects and analyze these factors with the relative importance index method. For this purpose, 83 different delay factors were identified, categorized into nine major groups, and visualized by the Ishikawa (fishbone) diagram through detailed literature review and interviews with experts from the construction industry. The relative importances of these delay factors were quantified by the relative importance index method. The ranking of the factors and groups were demonstrated according to their importance level on delay. According to the case study results, the factors and groups con- tributing the most to delays (those needing attention) were discussed, and some recommendations were made to minimize and control delays in construction projects. DOI: 10.1061/(ASCE)ME.1943-5479.0000129. © 2013 American Society of Civil Engineers. CE Database subject headings: Construction management; Scheduling; Turkey; Delay time. Author keywords: Construction projects; Relative importance index method; Schedule delay. Introduction A construction project is commonly acknowledged as successful when it is completed on time, within budget, in accordance with the specifications, and to stakeholders’ satisfaction (Majid 2006). In the construction industry, contractors tend to maximize their profit to increase market share. To achieve this aim, it is crucial for contractors to carefully identify the factors that affect the success of a project and estimate their impacts before the bidding stage. Construction projects may differ in size, duration, objectives, un- certainty, complexity, deadlines, and some other dimensions. Delay means noncompletion of the project within the specified duration agreed on in the contract. It is widely accepted that the schedule of a construction project plays a key role in project management due to its influence on project success (Luu et al. 2009). Delays are common in various construction projects and cause considerable losses to project parties. The common results of delays are late completion of the project, increased cost, disruption of work, loss of productivity, third-party claims, disputes, and abandonment or termination of contracts. Therefore, delays in construction projects give rise to dissatisfaction to all parties involved (Majid 2006). This research aimed to (1) identify the delay factors in construc- tion projects, (2) categorize the delay factors in construction proj- ects, (3) quantify the relative importance of delay factors and to demonstrate the ranking of the factors and groups according to their importance with respect to delays, (4) address the factors and groups contributing most to delays, and (5) make recommendations in order to minimize or control delays in construction projects. Literature Review The construction industry has a very poor reputation for coping with delays. Delay analysis is either ignored or done subjec- tively by simply adding a contingency. As a result many major proj- ects fail to meet schedule deadlines (Duran 2006). In Indonesia, Trigunarsyah (2004) reported that only 47% of projects were com- pleted within schedule, 15% were completed ahead of schedule, and 38% were behind schedule. Previous Studies As the process of construction project development is very compli- cated and combines various parties’ agendas, comprise many stages of work, and entail a long period until completion (Puspasari 2006), many factors contribute to delays in construction projects. Various researchers have examined and identified the causes of delays in construction projects. Some of these studies are presented below. Baldwin and Manthei (1971) investigated the reasons for delays in building projects in the United States. They indicated 17 delay factors. Their study concluded that weather, labor supply, and sub- contractors are the three major causes of construction delays. Arditi et al. (1985) studied the reasons for delays in publicly funded construction projects for the period 1970–1980 in Turkey. They concluded that 23 reasons accounted for the construction delays. Their findings indicated that the delays were due to a short- age of materials, difficulties in receiving payments from agencies, contractor difficulties, and organizational characteristics of con- tracting companies and public agencies. Ubaid (1991) discussed the performance of contractors as one of the major causes of delays. He related 13 major delay factors to contractor resources and capabilities. The causes of delays and cost overruns were studied by Mansfield et al. (1994) in regard to construction projects in Nigeria. The researchers identified 16 major factors. According to their 1 Associate Professor, Dept. of Civil Engineering, Middle East Technical Univ., Ankara, Turkey (corresponding author). E-mail: gunduzm@metu .edu.tr 2 Associate Professor, Dept. of Civil Engineering, Abu Dhabi Univ., Abu Dhabi, United Arab Emirates. E-mail: ynielsen99@gmail.com 3 Projects Control Manager, Botaş Petroleum Pipeline Corporation, Bilkent, Ankara, Turkey. E-mail: mustafa.ozdemir@botas.gov.tr Note. This manuscript was submitted on August 20, 2010; approved on April 2, 2012; published online on April 11, 2012. Discussion period open until September 1, 2013; separate discussions must be submitted for individual papers. This paper is part of the Journal of Management in Engineering, Vol. 29, No. 2, April 1, 2013. © ASCE, ISSN 0742- 597X/2013/2-133-139/$25.00. JOURNAL OF MANAGEMENT IN ENGINEERING © ASCE / APRIL 2013 / 133 J. Manage. Eng., 2013, 29(2): 133-139 Downloaded from ascelibrary.org by Qatar University Library on 04/17/16. Copyright ASCE. For personal use only; all rights reserved.