Figure 6: Simulation Arena in parking entrance Figure 7: Simulation Arena in parking exit 2.3.2 Module in Arena a Basic Process Module i.. Dispose Module: used to dispose of created enti
Problem statement
After a being complained by many IU students, by some decent researching and investigating, we have found that the Central Library’s parking system faces a very high number of students coming in during weekdays The problem is said that many students have to give up their choice to park in the Central Library’s parking system or wait for a very long time to get in Therefore, it is necessary to see whether the capacity of the recent parking system can contain enough customer vehicle flow into the Central Library and acquire a decent customer service level to gain satisfaction on operating.
Objectives
In this project, we embrace solving and finding the solution the following aspects:
• To see during weekday, how many vehicles will enter the system, how much time they will stay in the system, and related factors which will contribute to creating an appropriate result
• To see whether the recent parking system can satisfy the number of students and staff during the peak period with a high percentage in confidence
• To apply the knowledge from the Simulation course to find and design an approachable simulation model compared with the real system with technical skills and tools including input analyser, output analyser, validation,
• Proposing a conclusion along with suggestions for improvement on the IU’s parking system.
Scopes and Limitations
We will simulate the operation of the National University Central Library’s motorbike parking, located in No 40 National Highway 1A, Linh Trung Ward, Thu Duc City from 7 am to 5 pm
The data was collected by visual observation on Monday, April 26 th ,2021, therefore, all the time in and out of each motorcycle was not 100% precise Furthermore, because we cannot stay at the parking lot for several days to collect data, data are not correct for all working days In addition, the number of slots for each row was assumed as equal for easier creating simulation model
2 SIMULATION MODELING OF CURRENT SYSTEM
Figure 2: Inputs of the model
Figure 3: Content of the model
Figure 4: Outputs of the model
2.Total area: 420 m 2 with width: 28m and length: 15m
3.Total row: 6 rows from A to F with each row has 30 slots
- 1 gate: there is only one gate for students to enter or leave the parking lot.
- 1 POS machine (Point of Sale machine): uses for check-in and check-out process.
- 1 parking staff working at POS machine: this person gives, receives cards and collects parking fee
- 6 parking rows from A to F: the respective percentage of students entering row is 25%, 25%, 15%, 15%, 10%, and 10% This percentage is concluded based on position of the rows that is row A and B are the nearest ones to the gate and students would park here for convenient advantage Motorbikes will be stored in Store A to Store F
- 1 Sub Area: this area opens only when the 6 main rows are filled
At the beginning, students with their motorbike enter the parking station and check whether the parking lot is available or not Next, there are two situations; if the parking lot is already filled, the students cannot park there In contrast, they go to the POS machine to get parking cards Students, who have taken parking cards, are entering the parking lot If they pick row A, they will park at area A whenever the number of motorbikes is smaller than the capacity of area A, and then they go to the exit If there is no available position in the ordinary row, students will move to the next row When six rows are all filled, the parking lot needs to open the sub-area, which also has 30 slots
Students will go to the exit Gate in the log-out process, return the card and pay fees to the parking staff, and then move out
To analyze the working efficiency of the parking system, data was collected from 7 am to 6 pm which is the working time of the parking system
In this parking system, there are three types of data need to be collected including arrival rate, processing time and parking time
Arrival rate is defined as the number of entities arriving at the system per time unit In this case, we would collect the arrival rate of motorbikes which are parked in the parking system during the working time per minute When students access the parking entrance, the arrival time has been recorded To be specific, we divided the working time into three small period consisting of
7 am – 10:15 am, 10:15 am – 12:45 pm, and 12:45 pm- 4:00 pm and collected the data
In this study, the processing time is the total time an entity stays in the system It has been counted when students access and receive the parking card or return it and pay parking fee when they get out of the parking system We used second as the base time unit for processing time
Parking time is the total time an entity staying in the system It has been counted after the students receiving a parking card at the POS station until the students get their motorbike out of the system through POS station
After collection, we analyzed this data by using Input Analyzer in Arena software The data has distribution type as follows:
10:15 am – 12:45 pm POIS(0.713) 12:45 pm – 4:00 pm POIS(0.518)
Based on Chi-square test, the exactness of the model compared to actual observed data with a large enough sample size (n>50) is calculated and points out that the accuracy of the data has been valid If p-value of Chi-square test is greater than or equal to 0.05 because of a 0.95 confidence level, the data is more accurate
Waiting timeElevator's moving time
Figure 5: Simulation Arena in parking area
Figure 6: Simulation Arena in parking entrance
Figure 7: Simulation Arena in parking exit
2.3.2 Module in Arena a) Basic Process Module i Create Module: used to create entities which are defined to be Central Library’s students in this case study
Figure 8: Create module in Arena
Create module is defined as Vehicle in Parking system to account the numer of motorbike that come in the Parking system
(H is a variable that has initial value = 0.938.)
More explain in POIS(H): The aim is to have the create module with 3 different mean in the poisson distribution probability in 3 different time windows, To complete this, we build the following sequence:
From TNOW = 0 to TNOW = 195, H = 0.938 We use delay module to keep this variable
H can maintain in that amount of time Respectively, the next TNOW = 150 will give H 0.713, and the last part of period will give H = 0.518 ii Dispose Module: used to dispose of created entities as Central Library’s students who have finished their time cycle in the parking system and log out from it
Figure 9: Dispose module in Arena
Dispose module is set as End in Parking system to dispose iii Decide Module: used to perform decision – making processes of customers
Figure 10: Decide module in Arena
Decide module after getting a parking card and decide which row will the motorbike parked in
Table 3: Decide row module table move to the next row
Table 4: Decide parking module table iv Assign Module: Used to assign used to assign motorbike and people pictures for the entities have been created; and to assign values to variables, entity attributes, entity types, entity pictures, and other system variables (Waiting time, processing time, parking time)
Figure 11: Assign module in Arena
Assign module is set as Input/Output in Parking System to assign attribute, variable of motorbike into Parking system
Table 5: Assign module table Assignment Input:
- Atribute, TimeInSystem, TimeOut – Time in v Process Module: used to define the resources in the simulation system, including costing information and resource availability Resources may have a fixed capacity that does not vary over the simulation run or may operate based on a schedule Resource failures and states can also be specified in this module
Figure 12: Process module in Arena
Process modules are set as “Processing time IN/OUT” to define time that motorbike getting the card to enter the parking system
Table 6: Process module table Expression: UNIF(6,8.3)/ UNIF(9.5,18.5) vi Record Module: Used to collect statistics in a particular location in the model Once the requested statistic is collected, the entity exits from a single exit point of the module
Figure 13: Process module in Arena
Record module set as “Record A” in Output to determine the number of entities stored in Row A
Table 7: Record module table b) Advance Process Module i Delay Module: Used to delay an entity by processing time When an entity arrives at this module, the time expression defined in the processing time parameter is evaluated and the entity remains in the module for that period
Figure 14: Delay module in Arena
Delay module set as “Delay A” in Parking system to determine the delay time (parking time) at position A in Row A
Table 8: Delay module table ii Store Module: used adds an entity (motorbike) to storage When motorbikes arrive at the Store module, the storage specified is incremented, and motorbikes immediately move to the next module in the system
Figure 15: Store module in Arena
Store module is set as “Store A” in Parking System to add a motorbike into position A in Row A that the motorbike wants to park
Table 9: Store module table iii Unstore Module: used to remove the entity from the storage When motorbikes arrive at the Unstore module, the storage specified is decreased and motorbikes immediately move to the next module in the system
Figure 16: Unstore module in Arena
Unstore module is set as “Unstore A” in the Parking system to remove motorbike from the position A in row A that the motorbike has been parked
Experimental design
1 Time in, time out, and time in the system of each entity
We record and write out an excel file by read-write module as below:
Arrival Time Range 7:00:00 AM-10:00:00 AM
Entity Arrival time Departure time Time in system
Time Mins Time Mins Mins
15 7:12:06 AM 12.112 10:32:48 AM 212.814 200.702 ( The remain data can be seen in Appendix C)
2 At the end of 1 rep, in total, how many can the model hold?
After running 1 replication, it can be seen from the report that the model hold 620 entities in total In other word, there are 620 students who check in the parking lot and then logout
3 Can it hold enough students coming in?
As we can see from the picture above, the parking lot does not have enough capacity to satisfy the students’ needs of parking Therefore, the number of students has to leave and search for other place to park is 101 students.
Results and analysis
Arrival rate
A number of motorbikes per minute 7am -
Processing time
Parking time
Interarrival time
Parking time
Arrival Time Range 7:00:00 AM-10:00:00 AM
Entity Arrival time Departure time Time in system
Time Mins Time Mins Mins
Arrival Time Range 10:00:00 AM-1:00:00 PM
Entity Arrival time Departure time Time in system
Time Mins Time Mins Mins
Arrival Time Range 1:00:00 PM-5:00:00 PM
Entity Arrival time Departure time Time in system
Time Mins Time Mins Mins