การปรับปรุงประสิทธิภาพการดำเนินงานการก่อสร้างบ้านของโครงการบ้านจัดสรร ธีร์ทาวน์-ท่ารั้ว

Abstract

The objective of this independent research is to study how to improve Efficiency of House Construction operations of T Town-Tha Rua Housing Estate. Identify the cause of problem by interviewing 19 responsible staffs of T-town-Tha Rua Housing Estate and observing an on-site operation, using observational records, observational check sheets and interviewing reports. The collected data was analyzed by using Pareto chart and Cause and Effect Diagram to group the data to find the root causes of problems in construction operations include Value Analysis to identify non-value added activities. Then, adjust construction operations by Lean construction. After that, the result will be compared with data before operational adjustments. The result will be presented in the form of a percentage of project’s cost and decreased working days. The study of the current condition (before the adjustments), the results showed that the construction operations of one-story twin house have 49 main activities with 126 minor activities. The time spent in the project was 185 days in which some of the activities can be done in the same time. The empirical study showed that 627,093.37 Bath was spent on materials, 241,681.10 Bath was spent on wages, 739,500.00 Bath was spent on land (43.5 sq m.) development, 154,030.00 Bath was spent on selling expenses, 93,929.00 Bath was spent on administrative management and 88,753.31 Bath was spent on Tax (20%) resulting in a total net profit of 355,013.23 Bath. From the study and analyze the problem with Pareto diagram, it was found that the primary cause affect cost and operation time, namely waiting for operator, waiting for material, waiting for equipment and machine and operator’s malfunctioning. The problem-solving planning starts with investigation the construction blueprint and plans. Then, the non-valued added activities are identified and eliminated while an adjusted construction plan was created using the ECRS process. Such process includes Time function mapping, Gantt chart, On-time planning, Laborer management, Critical path method and Employee training plan by using Work Instruction (WI) and Flow Diagram to set the interoperability standard. By adopting the adjusted plan, cost of the second house decrease substantially. the results showed that able to reduce construction activities from 49 main activities with 126 minor activities, to only 49 main activities with 102 minor activities resulting in the reduction in time spent to 153.125 days, 31.875 days less than the first house. For construction cost, material cost was 622,576.40 Bath, wage cost was 241,681.10 Bath, land (43.5 sq m.) development cost was 739,500.00 Bath, selling expenses was 154,030.00 Bath, administrative management cost was 81,929.00 Bath and Tax (20%) cost was 92,056.70 Bath resulting in a total net profit of 368,226.80 Bath. The amount of money saved means the increase in profit of 13,213.57 Bath or 0.72% of house price.