การปรับปรุงประสิทธิภาพการดำเนินงานการก่อสร้างบ้านด้วยระบบผนังรับน้ำหนักแบบหล่อในที่ของโครงการหมู่บ้านสุขนิรันดร์

Abstract

The objective of this independent research was to study the methods for improving the efficiency of house construction operations using cast-in-place wall system of Sukniran Housing Estate. Identify the causes of problems by interviewing 21 staff of Sukniran Housing Estate and observing an on-site operation, using observational records, observation check sheets and interviewing reports. The collected data were analyzed using the Pareto Chart to group and analyze significant problems occurring in the construction process. The Cause & Effect Diagram is used to analyze the sub-causes of the problems, and the Value Analysis to identify non-value-added activities. Then, it was used to improve the construction process based on the principles of Lean Construction. After that, the result will be compared with the data before operational adjustments : the result will be presented in decreased working time and the form of a percentage of the project’s cost The study of the initial state (before the adjustments), the results showed that the construction of reinforcement two-story residential houses Using Cast in Place Load Bearing Wall System included 9 main activities with 75 minor activities. The time spent in the project was 105 days in which some of the activities can be done at the same time. Then, the empirical study showed that material expenses amounted to 691,699.13 Baht, labor expenses amounted to 429,793.96 Baht, administrative expenses amounted to 61,250.00 Baht, resulting in a total profit of 97,256.91 Baht. From the study of the problems through interviews and observations. These problems caused delays in the construction process. Therefore, the problems were analyzed using the Pareto Chart and the main problems with high significance and frequency were identified as follows: 1. Waiting for workers, 2. Waiting for tools and machinery, 3. Repairs and rework, 4. Design revisions, 5. Waiting for materials, 6. Insufficient expertise of worker, 7. Unclear work orders. The problem-solving planning begins with investigating the construction blueprint, structural models, construction process visualizations, and process improvement planning. The Value Analysis technique was used to identify non-value-added activities which were then used to develop a plan to adjust the construction process based on the ECRS. Such process includes Time Function Mapping, Gantt Charts, Process Flow Charts, On-time material planning, Labor plan, Laborer management, and Internal Management Plans. By adopting the adjusted plan, the construction wastes of reinforcement two-story residential houses decrease substantially. The results showed that able to reduce construction activities from 9 main activities with 75 minor activities, to only 9 main activities with 54 minor activities resulting in the reduction in time spent to 105 days, 31 days less than the first house. For construction cost, material expenses amounted to 664,370.51 Baht, labor expenses amounted to 420,813.96 Baht, administrative expenses amounted to 43,750.00 Baht, resulting in a total profit of 151,065.53 Baht. The amount of money saved means the increase in profit of 53,808.62 Baht or 4.20% of the construction project's value.