Selection of effective formwork system using multi criteria decision making analysis

Abstract

Formwork is the largest single cost item in constructing cast-in place reinforced concrete structure. This project focuses on analyzing the formwork selection problem based on decisive criteria. The factors affecting the choice of the exact formwork system have been often discussed in literatures but their importances have not been distinctly formulated. Therefore, a survey was conducted to recognize the decisive criteria in the formwork selection problems and ranking of the factors were carried out. A questionnaire formulated using google forms was sent to several respondents through email.74 responses were received and used for data analysis. The survey considered three types of currently used formwork systems with eight decisive criteria that affect the choice of formwork selection. Based on the 74 responses, the mean values for each decisive criterion were determined. Several methods that can be easily applied to solve the problem of formwork selection were identified. One of them is the TOPSIS (Technique for Order Performance by Similarity and Ideal Solution) algorithm, which is an easy to understand tool and can compute the best choice from the various alternatives of formwork system. Decisive criterion weights of mean values were calculated, and their weightage ordering was done by using Rank exponent method. Based on the ranking of decisive criteria, problems were discussed and suggestions were given to the respective problems. This project is concluded with comparing the results obtained from TOPSIS technique to responses from experienced site personnel in the construction industries and various suggestions in the formwork system were presented.