Manage Space for Construction Facilities on High-Rise Buildings

Poor usage of space at construction sites is one of the leading causes of decreased productivity in the construction industry; however, it is manageable, and some instances preventable. This study focuses on how to efficiently manage space for construction facilities on high-rise buildings in congested urban areas where space for facilities around the building footprint is not available. The construction facilities layout plan provides a logical order and priority for space planning decisions with reasonable costs. Genetic Algorithm (GA) modeling assumptions are made in order to properly allocate space for facilities that will result in lower computational costs and increased in productivity. Introduction Construction productivity is greatly influenced by the organization of the project site and the flow of equipment, labor, and materials through the site. The most important resource is space since materials should be stored so they are accessible when needed. Materials storage area should be selected carefully to avoid impacting construction operations, and materials procured by the general contractor should be inspected upon delivery to ensure that the correct items and quantities were delivered. However, like any resource, the amount of construction site space demanded by the various activities changes with the schedule of the work. Therefore, as the schedule evolves during the project, the site layout may need to be efficiently re-organized at various intervals to satisfy the upcoming schedule requirements to maintain construction site productivity (Emad et al. 2001). Problem Statement Space and time conflicts have been identified as one of the major causes of productivity loss in construction [Ahuja and Nandakumar (1984); Kuntz (1994); Oglesby, Parker et al. (1989); Rad (1980); and Sanders, Thomas et al. (1989)]. Sanders, Thomas et al. (1989) stated that efficiency losses of up to 65% are due to congested workspace and up to 58% are due to restricted access. Howell et al. (1993) reported the elimination of sharing resources, such as work areas, as a first step for performance improvement at construction sites, especially when a site is very tight or Copyright ASCE 2004 Construction Research 2003 2 highly constrained such as construction in an urban environment or facility rehabilitation. This paper presents a facility layout model for multiple floor buildings in high-density urban areas. Related Research The most common study in space management in the industry is through site planning. These plans are necessary to manage not only space on the site for material deliveries, staging areas, and crane locations, but also space in high-rise buildings that are normally situated in congested urban locations. The results from literature over the last decade can be classified into two broad area of study: (1) space-scheduling [Riley (1994); and Thabet and Beliveau (1997)]:and (2) site layout planning [Tommelein and Zouein (1993); Tommelein, Levitt et al. (1991); Yeh (1995); Lin and Haas (1996); Philip, Mahadevan et al. (1997); Gero and Kazakov (1997); Li and Love (2000); Zouein and Tommelein (2001); Tam, Tong et al. (2002); and Zouein, Harmanani et al. (2002)]. However, this paper considers both space-scheduling and site layout planning which is shown in Figure 1. Figure 1. Facility layout planning approach Note: In construction, there are multiple meanings for the word facility. For the purposes of this paper, a facility is considered a direct or support resource to be used in construction. For example, a facility could be a material pile, tool cart, or porta-potty. Multiple-Floor Facility Layout Explore In most cases, the approach is to take the shortest path from one major activity to another. The objective of multiple-floor facility layout is to minimize the total cost of material handling. The formulation of objectives can be expressed as (1): facilities of number m activities of number n D W Min n