EASTERN MEDITERRANEAN UNIVERSITY
FACULTY OF ENGINEERNG
Department of Industrial Engineering
IENG461 System Modeling and Simulation Course
Fall 2012-2013
Laboratory Session 01
Open Microsoft office> Microsoft Excel
File> New> Blank Workbook
IF FUNCTION
Formula: =if(condition,expression1,expression2)
Example1:
TRUE
FALSE
Write the formula in C2
Enter and drag outside selection to extend series.
A NESTED IF FUNCTION
Formula: =if(condition1,expression1,IF(condition2,expression2,expression3))
Example2:
Write the formula in C2
Enter and drag outside selection to extend series.
Using an AND condition in an IF function
Formula: =if(AND(condition1,condition2),expression1,expression2)
Example3:
Both True
Any of them is wrong
Write the formula in C2
Enter and drag outside selection to extend series.
Using an OR condition in an IF function
Formula: =if(OR(condition1,condition2),expression1,expression2)
At least one True
Example4:
Both wrong
Write the formula in D2
Enter and drag outside selection to extend series.
Using LOOKUP Function
LOOKP tables are used when you want to compare a particular value to a set of
values, and depending on where your value falls, assign a given answer.
Formula: =VLOOKUP(lookup value, table_arrey, col_index_num, [range lookup])
Example5:
Write the formula in G3
Enter and drag outside selection to extend series.
Example6:
Lets say you want to assign letter grades to students based on a pre-spesified scale,
which is shown in the following table.
VLOOKUP
HLOOKUP
Vertical Lookup
Horizontal Lookup
HLOOKUP Example
Example7: Using HLOOKUP function of excel, find matching departments of the
following instructors:
Power Example
Example8:
Formula: =POWER(number,power)
Mod Example
Example9:
Formula: =MOD(number,devisor)
Countif Example
Example9:
Formula: =Countif(range,criteria)
Random Number generation
Formula: =RAND()*(b-a)+a
Random number
between a and b
When you use above formula each time that you open excel the generated random
numbers will change. To stop this automatic change you should do following
adjustment:
File>Option>Formulas>Manual> remove Recalculate thick> OK
Lab HOMEWORK#1:
A small grocery has only one checkout counter. Customers arrive at this checkout
counter at random from 1 to 9. each possible value of inter-arrival time has the
different probability of occurrence as shown in table 1 below. The service times vary
from 1 to 6 minutes with the probabilities shown in table 2. the problem is to analyze
the system by simulating the arrival and service of 20 customers by using simulation
table.
Table1. Distribution of time between arrivals
Time Between Arrivals (minutes)
Probability
1
0.12
2
0.225
5
0.13
7
0.225
8
0.14
9
0.16
Cumulative Probability
Random-Digit Assignment
Table2. Service Time Distribution
Service Time (minutes)
Probability
1
0.1
2
0.2
3
0.3
4
0.25
5
0.1
6
0.05
Cumulative Probability
Random-Digit Assignment
The random digits between arrivals (3 digitsis needed) and service times (2 digits is
needed) are going to putted in table 3 and 4 respectively.
Table3. Random digits for time-between-arrivals determination
Customer
Random digits
Customer
Random Digits
1
11
2
12
3
13
4
14
5
15
6
16
7
17
8
18
9
19
10
20
Table4. Random digits for service time determination
Customer
Random digits
Customer
Random Digits
1
11
2
12
3
13
4
14
5
15
6
16
7
17
8
18
9
19
10
20
Conduct a simulation of the above system by using EXCEL and find the following
performance measures related with the system:
• The average waiting time for a customer and probability that a customer has to
wait.
• The average service time and average inter-arrival time.
• The average time a customer spends in the system .
• The average waiting time of those who wait.
The End