Literature review on lean implementation cases in the construction process

Lean construction is a concept still new to many construction industries in the world. All construction activities can be divided into two; conversion activities which produce tangible and flows activities which bind such conversion activities during the delivery process of the output. Although all activities expend cost and consume time, Lean Principles state that only conversion activities add value and these should be made more efficient, where as non value-adding flow activities should be reduced or eliminated. By eliminating wasteful non value-adding activities, processes can become 'lean' which provide 'more with less' resources. Research into these lean principles in construction has found that considerable waste lies in flow activities of the construction process. However, the construction contractors are mainly aware of the waste associated with material usage during the construction process and are ignorant on wastes associated with flow activities. Previous research has found major causes and types of wastes in flow activities and also that they significantly hinder performance and efficiency in the Sri Lankan Construction Industry. Hence, it is high time that the Sri Lankan construction industry start considering lean construction to improve its overall performance. However, Sri Lankan construction industry lacks an implementation framework to implement lean principles into the construction processes. The research study, on which this paper is based on, ultimately aims to develop such an implementation framework through an action research study for Sri Lankan construction contractors. Other countries such as United Kingdom, United States of America, and Singapore have reaped sustainable benefits through proper implementation of lean construction. Extant literature offers several case studies on such lean construction implementations. Hence, this paper offers a critique on these case studies, as an initial step to develop an implementation framework for Sri Lanka. Accordingly, few case studies are critically compared with their construction settings. The findings reveal several similarities in the lean implementation in different settings and deviations are also identified. The paper finally, identifies the mot commonly applied lean techniques for implementing lean principles in construction process and benefits. It is hoped that the key literature findings arising from this stage, will ultimately assist to develop a concetual implementation framework using lean principles for the construction process.