Lean strategies to minimize waste in Sri Lankan quarry industry

Abstract

Aggregates product is one of the main contributors to the construction industry. According to the GSMB records, the total annual production of crushed and broken rock is about 10 million cubic meters. Due to the rapid increase of construction industry, the demand for the rock is also increasing and it will help to increase the number of metal quarries in the country. Therefore, there is a need to enhance quantity and productivity of process in industrial quarry projects. It is very difficult to find a systematically well-developed quarry although there is a high demand for aggregate product in Sri Lanka. It is observed that there are many non – value adding activities (waste) in their processes which hinder the quarry performance. Therefore, there is a need to implement concept such as lean philosophy in order to eliminate or minimize waste and to optimize quarry operation. Accordingly, aim of this research is to identify lean strategies to minimize waste in Sri Lankan quarry industry.One of the objectives of this study was to identify lean concept and main industrial waste. This objective was successfully achieved through a comprehensive literature survey and end of the literature review the conceptual model for the study was developed. Multiple case study method under qualitative research approach was selected as the most suitable research method for this study. Three industrial quarry sites were selected under the multiple case study design. Data collection for the case study was based on semi structured interviews based on the open ended questions to enhance the richness of the information collected. Data were analyzed adopting content analysis, tables and cognitive mapping techniques. Cognitive map was developed for all identified factors affecting waste in Sri Lankan aggregate mining industry under main eight waste which are Over Production, Waiting/ Delay, Unnecessary Transportation, Unnecessary Processing, Excess Inventories, Unnecessary Movement/ Motion, Defects, Underutilised People . The proposed strategies for each factor were linked to relevant lean strategy by considering literature review and desk study. Finally, initially developed conceptual model was modified to prepare a framework to minimize waste (non-value adding activities) in Sri Lankan quarry industry by using lean strategies as the final outcome of the research. Accordingly TPM, JIT, Bottleneck Analysis, PDCA, 5S, Kaizen, TQM, Poka-Yoke, Jidoka were identified as key lean strategies to minimizes main eight waste in quarry industry