Journal of Construction in Developing Countries, 18(1), 53–72, 2013 © Penerbit Universiti Sains Malaysia, 2013 Analysis of Non-Excusable Delay Factors Influencing Contractors' Performance in Lagos State, Nigeria Olajide Timothy Ibironke, Timo Olugbenga Oladinrin, * Onaopepo Adeniyi and Idowu Victor Eboreime 1 Abstract: Delays are one of the biggest problems faced by construction firms. The objectives of this study are to identify non-excusable delay factors, their effects on project completion and means of minimising these delays. A questionnaire survey was conducted to solicit the causes, effects and methods of minimising delays with two groups of respondents: consultants and contractors. Data were collected and analysed using a weighted mean method. A total of 57 major factors that cause non-excusable delays were identified from the reviewed literature and were further classified into eight major groups. The findings of this study revealed 20 key factors that cause non-excusable delays. The resultant effects of non- excusable delays are time overrun, cost overrun and disputes, among others. Ensuring adequate financial sources, engaging competent project managers and making all necessary resources available are some of the most important means of minimising non- excusable delays. Since non-excusable delays are specific to contractors, this study concludes that contractors should review their activities so that construction work will not be delayed. Keywords: Non-excusable delays, Contractor, Cost overrun, Time overrun INTRODUCTION Construction projects are one-off endeavours with many unique features, such as long time spans, complicated processes, extremely challenging environments, financial strain and dynamic organisation structures (Zou, Zhang and Wang, 2007). Delay can be defined as a situation when the contractor and the project owner jointly or severally contribute to the non-completion of the project within the original, stipulated or agreed upon contract period (Aibinu and Jagboro, 2002). Clients or consumers are no longer content with only satisfying minimal cost, adequate functional performance, increasing interest rates, inflation and other commercial pressures, but are also concerned with using the shortest possible amount of time to complete the building project (Nkado, 1995). Ajanlekoko (1987) observed that the construction industry showed poor performance in terms of time. Seven out of 10 projects surveyed in Nigeria suffered delays in their execution (Odeyinka and Yusuf, 1997). Ozdemir (2010) asserted that the construction industry has a very poor reputation for coping with delays. Delay analysis is generally either ignored or performed subjectively by simply adding a contingency. As a result, many major projects fail to meet scheduled deadlines. In a construction project, in which time truly equals money, the management of time is critical (Duran, 2006), thus predicting a likelihood that schedule delay plays a key role in overall project success (Luu et al., 2009). The foremost concern of every contractor is to ensure that the highest possible performance level is achieved in construction project 1 Department of Quantity Surveying, Federal University of Technology, Akure, Ondo State, NIGERIA ∗ Corresponding author: firstadeniyienoch@yahoo.com