An Implementation of Lean Approach to Achieve Working Time Efficiency in Precast Factory

Abstract

Question: Can the 5S lean approach using Seiri (Sorting), Seiton (Arranging), Seiso (Cleaning), Seiketsu (Standardizing), and Shitsuke (Sustaining) improve the workflow to achieve efficiency in the working time needed to produce Corrugated Concrete Sheet Pile (CCSP)? Purpose: The aim of this study is to offer modification of work processes by implementing a lean approach using 5S to eliminate waste and improve working time. Research Method: Data were collected by practitioner interview and in-depth observation to obtain a completed understanding work process of the precast production cycle. Then, Bizagi Modeler 2.0 was used to determine the mapping of the production cycle and the total time duration. Process Activity Mapping is used to determine the problems contained in the cycle, especially activities that are NVA. Then, a modification of work processes used a lean approach with 5S concept to eliminate non-value added (NVA) activities and achieve working time efficiency. Findings: Based on the research results, it was found that there were two problems in the CCSP concrete production cycle. The first was the strand cutting activity, delayed since it was performed with a lack of workers. The second was the delivery ready mix was categorized as a delay activity that needs to be eliminated. Both of these problems were addressed with 5S. Seiri is applied by doing a standard operating procedure completed with the number of workers for each work item. At the same time, Seiton concepts are conducted by moving the batching plant. The improvement has resulted in: a decreased execution time of strand cutting from 129.23 minutes down to 64.8 minutes (50%), an elimination of delivery ready-mix as a delay activity (NVA activity) which can save 15.13 minutes of production time, and a shortened working time of concrete bucket loading from 10 minutes to 5 minutes (50%). All the working time savings are obtained in the production cycle. Before the improvement it took 33 days to complete 25 production cycle of CCSP. After the improvements the 25 CCSP production cycle took 31.5 days (4.5% efficiency). Limitations: This study mainly focused on a 5S lean approach with Bizagi Modeler software and Process Activity Mapping method at a precast factory producing CCSP. Implications: This research will provide guidance for applying the 5S lean approach relative to time efficiency in a construction company and can also inspire further research to develop alternative lean approaches. Value for Practitioners: This paper presents the impact of applying the 5S lean approach to minimize wastage in the production cycle in order to achieve time efficiency, with an emphasis on construction supply factories wishing to adopt lean. Keywords: 5S, Bizagi Modeler, Lean Approach, Process Activity mapping, Time Efficiency Paper type: Case Study