269 publications from this institution
The effects of construction delays are not confined to the construction industry but influence the state of the overall economy of a country. This is particularly so in Turkey where construction investments account for almost half of all investments and where delays have reached significant magnitudes in the 1970–80 decade. A Iurge number of public agencies that are construction owners and a large number of contractors that undertake construction work for public agencies in Turkey were surveyed to identify and rank in an order of importance the causes for such delays. The results indicate that shortages of some resources; public agencies' and contractors' fincincial dfiiculties; organizational deficiencies and delays in design work, frequent chunge orders and considerable extra work are the most important sources of delay. While some of the causes are dependent on national economic policies, others may be overcome by measures to be taken by public agencies and contractors.
Since the selection of a delay analysis method depends on the delay analyst's subjective judgment, there is a risk of making problematic decisions due to the delay analyst's ignorance, lack of experience, carelessness, or intention. Each one of these methods may yield different analysis results. Therefore, it is necessary to develop an objective decision-making system based solely on the project environment. The existing delay analysis methods are classified into four types, according to the basic principles used in the analysis. Seven conditions that affect the selection of a delay analysis method (i.e., type of schedule, type of information, timing of analysis, expectations from the delay analysis, acceptance by courts of law, capabilities of delay analysis team, and budget constraint) were identified in a literature review. A delay analysis selection system (DASS) was developed using if-then rules constructed by considering which conditions should exist in a given project environment for successfully performing a specific type of delay analysis and getting realistic results. This system was computerized and validated by implementing it in several but different scenarios considered in this study. The contributions of this study include (1) an objective selection decision can be made based on only the project environment, without relying on the analyst's subjective preference, and (2) unnecessary and expensive legal disputes caused by delay-related issues between construction owners and construction companies can be minimized.
