Bloemfontein: Central University of Technology, Free State
Abstract
Published ThesisThe construction design process (CDP) is made up of five distinct phases. The phases include the inception design phase, the predesign phase, the detailed design phase, the construction phase (CP), and the close-out phase (COP). With the exception of the COP, the above-mentioned phases in the CDP are fraught with non-value-adding (NVA) activities that are otherwise called ‘waste’ in the lean terms. These wastes hinder the efficient delivery of projects in the construction industry. To overcome this dilemma, researchers worldwide have investigated how waste in the CP of a project can be eliminated through lean principles. However, the findings in the literature indicate that attention is focused mainly on the architectural process (AP) while the structural design process (SDP) is largely uncovered. In an attempt to bridge this gap, this research investigated the various waste that originate from the SDP, the causes of the waste, their impacts on projects, and how such waste can be eliminated. The study was executed through an action research design. Primary data were collected from five consulting engineering firms (CEFs) in Bloemfontein, South Africa. The engineers have extensive experience in the SDP, and are affiliated with the Consulting Engineers South Africa (CESA). To effectively identify, and confirm the various waste types in the SDP, a lean tool known as value stream mapping (VSM) was also deployed in the current flow of the activities in each phase of the SDP. That is, the VSM adopted in the study enabled the researcher and the study group in each firm to reaffirm the existence of the identified NVA activities in the SDP, and to explore more waste in the practice. Having compiled the various wastes in the system, the study proposes different strategies that can be adopted to reduce the identified waste. The proposed strategies were used to develop a lean or VSM mechanism that was used to execute a new project in one of the case study firms. The findings from the study reveal that waste exists in every phase of the SDP. Typical examples of these waste are waiting time, error, over-processing, excessive vigilance, motion, clarification, overproduction, work interruption, and rework. The findings in the study also indicate that some of the identified waste in the SDP, such as error and clarification, often lead to delay in the design phase, which consequently leads to delay in the start of the construction activities, and the completion time of a project. The identified waste in the SDP also contributes to poor project delivery and cost overrun. The study concludes that the lean concept can be extended to the SDP to eliminate waste in practice. This implies that the proposed mechanism in this study offers guiding information on how lean concept can be adopted to identify and reduce waste in the SDP. The mechanism also serves as a platform that allows structural designers to identify gaps in their implementation efforts, focus attention on areas for improvements and assess the benefits of the lean approach in the design and the construction phases of projects. The research recommends that VSM, and the five lean principles should be adopted by structural designers in every phase of the SDP for waste eradication
