World Construction Conference 2012 – Global Challenges in Construction Industry 28 – 30 June 2012, Colombo, Sri Lanka 100 MAINTAINABILITY APPROACH FOR LEAN MAINTENANCE Nayanthara De Silva* Department of Building Economics, University of Moratuwa, Sri Lanka Malik Ranasinghe and C. R. De Silva University Moratuwa, Sri Lanka ABSTRACT The concept of lean maintenance is promoted to eliminate maintenance waste and to maximise efficiency of the manufacturing process for overall cost reduction. The optimum usage of labour, material and technology is thus, proposed to eliminate waste during the maintenance process. This paper proposes a maintainability approach to minimise maintenance waste in order to promote lean maintenance concept to the construction industry. The approach has widened the focus of existing lean maintenance concept by moving it boundaries from the maintenance phase to early phases of the development process. Eight challenges of lean maintenance have been established from fifty one maintainability causes of high-rise buildings. Their impact to maintenance cost was evaluated using a case study and found 40% reduction in the maintenance cost as wastage. Keywords: Lean Maintenance, Building Maintainability, Maintenance Cost, High-Rise Buildings. 1. INTRODUCTION The concept of lean maintenance which originated in the manufacturing industry is known as a systematic approach to identify, analyse and eliminate waste through proper management and continuous improvement (Bagadia, 2009). In the construction industry, the concept of maintainability of buildings focus on achieving efficient maintenance by eliminating waste in maintenance cost for rectifying maintenance deficiencies (De Silva, 2012). Thus, in turn this concept of maintainability promotes lean maintenance due to its similar focus on minimising waste. The causes for deficiencies in maintenance can be considered as maintainability risks (Low and Chong, 2004; Wong and Hui, 2005; Flores-Colen et al., 2008; De Silva and Ranasinghe, 2010). These risks are not occurred only during the maintenance phase of a building (De Silva and Ranasinghe, 2010; De Silva, 2012). They can moreover be originated from poor design and construction practices. Poor accessibility for maintenance, inadequate design detailing, poor quality and incompatibility of materials, poor specifications, non availability of spare parts, lack of standard tools and instruments for regular maintenance were some of the highlighted design and construction related risks which incur many wastes in terms of financial losses in maintenance (Shabha, 2003; Chew and De Silva, 2003; Chew et al., 2004; Low and Chong, 2004; Wong and Hui, 2005; Flores-Colen et al., 2008; De Silva and Ranasinghe, 2010). In addition, lack of maintenance policies and strategies, budgets, skills, technology are identified as some such risks faced during the maintenance phase of buildings (Shabha, 2003). These risks can also be defined as contributing factors for waste in maintenance and thus, are referred as “challenges of lean maintenance.” Costly, difficult and unsafe maintenance are recorded in the literature as a result of above deficiencies, increasing waste in maintenance (De Silva, 2012). For instance, Ramly et al. (2006) reviewed 4,389 records from 36 public housing areas in Kuala Lumpur, and found that 47% were caused due to design faults. There were 11,625 maintenance records which identified inferior quality of construction as the cause for houses built between 1982 to 1999 in Victoria, Australia (Mills et al., 2009). Chong and Low (2006) found that nearly 60% of latent defects can be preventable with better design, 33% with better * Corresponding Author: E-mail - endds@becon.mrt.ac.lk