Simulation Modelling and Analysis of Impact of 3D Feedback Workflow on Prefabrication of Industrial Construction

Abstract

The construction industry has not been experiencing the same level of productivity increase as the manufacturing industry, due to their divergent production methods. While traditional construction projects are unique, craft-based, and typically done on-site, manufacturing is able to mass produce standardized products on assembly lines in a controlled environment. Efforts to improve construction productivity take advantage of the more established and mature manufacturing processes and techniques, such as modularization and off-site assembly. As civil industry work requirements become more demanding, and modular component tolerance continues to decrease for more complex projects, there exists a need to incorporate and utilize quality control technologies similar to what have been used in the manufacturing and automotive industries for years. Rework of items that failed quality checks leads to significant waste of resources, resulting in reduced overall productivity represented by additional time and manpower spent on correcting the errors. The solution set to this problem ultimately needs to address lost productivity due to rework, and generate value from its operation in the industrial fabrication workflow. The use of 3D data acquisition and 3D feedback is proposed to be part of the quality control process of pipe spool fabrication, which takes place during fitting and before shipment to site. The existing prevailing workflow and the proposed workflow using the new technology are assessed using discrete-event simulation, and three implementation scenarios are investigated, which are: (1) nuclear projects, (2) small bore non-nuclear projects, and (3) large bore non-nuclear projects. They represent different quality control processes for their particular requirements, as well as their specific activity process times given the nature of their assemblies. The analysis of the simulation results show that the revised workflow improved performance for all three project types, specifically in rework reduction and overall fabrication time reduction. Risk assessment was also carried out, in order to quantify the risk mitigation and accrued benefits by implementing the revised fabrication workflow for pipe spool assembly. The difference in risk was considered as a project benefit under economic analysis, and it was found that the relatively short payback period for the fabricator justifies the initial technology investment required to set up the platform for 3D feedback in the revised workflows.