are produced. Process continues calculating the round trip time. As, the round trip time obtained from calculations, model finds the number of elevators required in specified speed. Then, performance criterions handling capacity, average travel time, average waiting time is calculated according to specified number of elevators. Finally, for a specified speed and number of elevators the car capacity and the area of elevators occupy a place in the plan layout is calculated. The whole process is repeated for the second alternative speed. After finishing the calculations, all results for three alternatives are transfered to a spreadsheet via add-on that connects Grasshopper to MS Office Excel. According to results of three alternatives, if the performance results are within the target values, then the alternative with the minimum number of elevators is designated as the result. If all alternatives have the same number of elevators, the result is chosen as the one, which has the minimum speed. Unless, all results satisfy the performance criterion then, the second part of the model starts. The second section is optimizing solutions. To increase the number of elevators, a zoning policy is implemented. Zoning is the method to split the building into zones. If the average travel time is larger than 90 seconds or the number of elevators is more than 9 elevators, model splits the building into zones. For 32
MSTAS 2015
each zone model finds the number of elevators, speed and capacity by traffic calculations as in the first section. Zoning policy of the model uses general rule of thumb, which is splitting total number of building floor to 60% to 40%. As an output, the optimization section crates again three alternatives for each zone, separately. The important criterion in the zoning is selecting the same number of elevators for each zone. Like the design generation section, three alternatives are created for three different elevator speed. The number, capacity, dimensions and shaft area needed is defined as an output. After all calculations are finished, the model proposes only one alternative as an optimum solution if there is no zoning result. Otherwise, the model proposes two alternatives; the solution without zoning and the optimum solution for zoning to give selection chance to user. All design alternatives and results are transferring into an Excel file to demonstrate. 3.2. Input Parameters Inputs used in the model can be categorized into three as building data, traffic data and elevator data. The first one is building data that can be also named as project data, as it consists of user defined building parameters. The second type of input is traffic data that consists values derived from past researches and used as target traffic values for building (Figure 3). Traffic data can be user defined