## 2 Multi-Criteria Model of Temporary Facility Layout Planning in Construction
### Identification of Layout Factors and Objectives
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**Criterion** & **Sub-Criteria** & **Influence on the Layout Planning** & **References** \\ \hline \multirow{8}{*}{Safety (S)} & & It refers to the safety of temporary equipment operation during construction, such as tower crane, mobile crane and scaffoldings. OSHA (Occupational Safety and Health Administration) requires the contractors to provide protection and safety measures against falling objects especially below steel erection operations. & [2, 31, 32, 33, 34, 35] \\  & & In order to avoid construction site accidents, such as falling objects, hazardous substances and prohibited areas, proper “safety zones” and minimum distance between hazardous facilities and other temporary facilities should be taken into consideration. & [1, 35, 36, 37, 38] \\ \hline \multirow{8}{*}{Control of hazardous material (CHM)} & It refers to the movement and store of hazard materials in construction. In temporary structure layout planning, excessive movement of materials should be avoided, and the proper store and control of hazardous material are required. & [5, 8, 17, 39] \\ \cline{1-1} \cline{2-3}  & & Temporary facility layout significantly impacts the moving cost of resources, including labor, material, and equipment. Frequent movements of resources can cause safety hazards and accidents when the travel routes of these resources intersect. Therefore, minimization of the total number of intersections on site helps improve safety and minimize the risk of accidents. & [2, 8, 40, 41, 42, 43] \\ \hline \multirow{8}{*}{Productivity (P)} & The task execution requires temporal and spatial requirements during temporary facility setting up and dismantling process. Improving the efficiency and safety of task execution on site canyon support the temporary facility layout planning in construction. & [11, 36] \\ \hline \multirow{8}{*}{Productivity (P)} & Effective space utilization (ESU) & Construction site space can be classified into various types. According to the relative importance, the site space utilization can be improved by analyzing workspace and risk on the jobsite to support site planning. & [36, 44, 45, 46] \\ \cline{1-1} \cline{2-3}  & & Workspace inside/around temporary facilities provides labor crews with adequate space to execute and complete the activities. The productivity and ergonomics (LPE) & \\ \cline{1-1} \cline{2-3}  & & Supported by temporary facilities, such as cranes and scaffolding, can affect the plan decision to reduce rework and improve efficiency of temporary facility planning. & [11, 47, 48, 49] \\ \hline \multirow{8}{*}{Short construction duration (SCD)} & Effective layout planning of temporary facilities provides the construction planners with a proper positioning of temporary facilities and enables short moving paths of materials and equipment, which leads to short construction duration and cost saving. & [17, 50, 51, 52] \\ \cline{1-1} \cline{2-3}  & The ability to dynamically change the TFs (ACT) & Construction site changes over time dynamically, which may lead to on-site congestions. To reduce congestions, the ability to meet the requirements of temporary facility layout and arrangement needs to be improved. & [17, 24] \\ \hline \multirow{8}{*}{Cost (C)} & Facility sequt (PSC) & The temporary facilities positioning involving in site layout planning determines the facility setup cost. & [11, 56] \\ \cline{1-1} \cline{2-3}  & Facility removal cost (FRC) & The facility removal cost is affected by layout planning due to the relocation times and facility setup times. & [11, 56] \\ \cline{1-1} \cline{2-3}  & Resource travelling cost (RTC) & The resource travelling path and congestion determined by temporary facility layout planning directly impacts the resource travelling cost. & [4, 8, 11, 44, 56] \\ \cline{1-1} \cline{2-3}  & Resource handling cost (RHC) & The objective of temporary facility layout problem is to minimize the material handling cost or resource movement cost inside a facility. & [2, 56, 57] \\ \cline{1-1} \cline{2-3}  & Worksite personnel visit cost (WPC) & The personnel travelling path and work crew movement distance are significantly affected by the temporary facility layout solution. & [35, 56, 57] \\ \hline \hline \end{tabular}
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