# Automated Generation of Daily Evacuation Paths in 4D BIM
## 5 A Case Study and Implementation
### Step 2: Prepare User Input  
The second step is to generate non-building components, such as workspaces, temporary structures, and exits. Four milestones that represent the status and progress of each construction activity in the associated domains were defined and used to generate the four sub-BIM models. For the easy organization of work processes and orders, the general contractor of this construction project split the work zone into seven areas (Figure 4b). For example, Scenario Model 1 involves building and site conditions of construction on May 20 th 2014, which illustrate foundation work in area 3 and steel structure work in area 2 and 3. The construction work activities and site conditions on May 20 th are diagrammed in Figure 6. Each sub-BIM model contains information and its properties pertaining to a work crew location, a work zone, a material stack, a completed structure, an exit, and other factors that can impact generation of evacuation paths.  
Figure 4: (a) BIM model and (b) work zones of case study project.  
Figure 5: Construction schedule and four milestones.  
Scenario Model 1 shows the following three working processes: (1) Foundation work in the area 3, (2) structure work in area 2 and 3, and (3) MEP work in area 3. Each domain activity is color-coded on the floor plan to efficiently represent the types of construction work. On May 20 th, area 3, having a concrete foundation task with a reinforcing bar (rebar) installation, is only accessible from the nearest exit in yellow. In other words, rebar workers can use the exit in the upper side of the floor plan, but structure steel workers cannot use it for the evacuation path. Thus, the accessible exit for steel workers is the one located in the bottom of the plan. In addition, each work activity entails associated materials. The location and the area of materials such as a rebar stack is an imperative component for evaluating real-time evaluation planning. However, this manuscript does not involve any formulized and generalized information about work types, areas, and considerable parameters because construction projects generally involve significantly distinct and unique project types, program requirements, tasks, and a schedule that result in different site conditions. For the real-time evacuation analysis, this information can be manually tailored and updated by a BIM modeler according to a project and site information.  
Scenario Model 2 shows the following five working processes (Figure 7): (1) Foundation work in area 6, (2) structure work in area 5 and 6, and (3) masonry work in the east side, (4) MEP work in area 1 and 6, and (5) roofing work in area 2. On July 2 nd, the roofing work area containing scaffolding cannot be used as an accessible evacuation pathway because of the shallow path spaces, the complex scaffolding structure, and the low illumination level of the area.  
Scenario Model 3 in Figure 8 shows the following three working processes: (1) Masonry works in the west side, (2) MEP work in area 3 and 5, and (3) roofing work in area 7 and 7-2.  
Scenario Model 4 in Figure 9 shows the following two working processes: (1) Masonry work in the east and west sides and (2) MEP work in area 1.  
Figure 6: Scenario Model 1: Work status and site conditions.  
Figure 8: Scenario Model 3: Work status and site conditions.  
Figure 7: Scenario Model 2: Work status and site conditions.