Relationship model of constructability and cost performance for Indonesia state building project

Abstract

Constructability and cost are directly related to each other; when the complexity increase, the cost will also increase. Controlling the design, bid and build in terms of constructability helps to better manage the cost performance of projects. Hence, this study is to investigate the relationship model between constructability and cost performance of government building project in Indonesia at design, bid and build stage. Implementing constructability at the beginning of a design, bid and build could have an impact on cost performance results. By increasing the application of constructability innovations and managing its barriers can optimize the cost performance. The relationship model approach H1 is the relationship between constructability to the design stage, H2 is the relationship between the design to the bid and build stage, H3 is the relationship between the constructability to the bid and build stage, H4 is the relationship between the constructability guidelines and standards against cost performance. Data collection using questionnaire are obtained from design professional respondents, contractor/sub-contractor, supplier/vendor and government project owner or their representatives (construction management consultant). Hundred (100) respondents were selected from infrastructure projects and further hundred (100) respondents were chosen from building projects. From the survey, fifty (50) respondents of building projects and forty-six (46) respondents from infrastructure projects responded to the survey. The first stage of the survey is to attest the questions and variables, the second stage of survey is to obtain the data of the study. The Likert scale answers, and other forms were used. The data are then processed through the common perception of questions with homogeneity using SPSS. The data were also tested for reliability using SEM PLS, where they were then analysed in accordance to the objectives. From the results: H1 exhibits seventy-two (72) percent of respondent strongly agreed that constructability implemented at the design stage by the independent reviewer/Construction Management Consultant for projects more than four (4) floors of high rise building or more than 5000 Square meters of floor areas or more than one Designer involved. H2 exhibits sixty-five (65) percent of respondents strongly agree that during design stage the design consultant had incorporate the building standard, bidding/contract and consideration of easier method of construction. H3 exhibits eighty-one (81) percent of respondents agreed that the bidding process was conducted to select a contractor that has a cheaper and reasonable price which can be relied upon during construction. H4 exhibits seventy-four (74) percent of respondents strongly agree that constructability implemented by using the standards and guideline as well as compliance to the requirements, help the cost performance to meet by the project owners budget. In this study it was concluded that the relationship model between constructability and cost performance at design, bid and build stage as project delivery method can be used to control project cost performance.