Lean Construction strives for reliable workflow on the construction site by using work-structuring and the Last Planner System. In the construction industry, many factors contribute to unreliable workflow such as late delivery of material and equipment, blue-print errors, change orders, equipment breakdowns, tool malfunctions, improper resources utilization, labor strikes, and environmental (weather) effects. Another important source of variability, which is often overlooked is construction waste, as in by-products of the construction process. This source of reliable workflow impedance create cluttered, congested, and dangerous work conditions. In Lean Construction, 5s or 6s is deployed in order to mitigate the effects of construction waste. Another tact to use, which follows from the continuous process improvement spirit that underlies lean, is to minimize and ideally eliminate this waste. If dealt with appropriately, there can be many benefits, including lower overall cost, faster production, a higher quality, and more sustainable buildings. The purpose of this investigation is to ascertain key sources of construction waste, and whether generation varies with the type and size of the constructions. A sample of 30 general contractors was studied, and several null hypotheses on waste generation and minimization differences were tested using the Kruskal-Wallis H test. Although subtle shifts were observed in the aspects of waste behavior that seemed predicated on construction sectors and capital base, to some extent the proposition that construction type and size can influence waste generation and minimization was validated. Based on this study, some solutions are provided as viable avenues to managing and minimizing construction waste.
lean construction, construction waste, workflow problems, waste minimization
Ilozor, B.D. , Egbu, C.O. & Abdelhamid, T.S. 2008, 'Designing and Building to Minimize Construction Waste' In:, Tzortzopoulos, P. & Kagioglou, M., 16th Annual Conference of the International Group for Lean Construction. Manchester, UK, 16-18 Jul 2008. pp 743-768