EASTERN MEDITERRANEAN UNIVERSITYFACULTY OF ENGINEERNG

Department of Industrial Engineering

IENG461 System Modeling and Simulation CourseFall 2012-2013

Laboratory Session 01

Open Microsoft office> Microsoft Excel

File> New> Blank Workbook

IF FUNCTION

Formula: =if(condition,expression1,expression2)

TRUE FALSEExample1:

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)

Both True Any of them is wrongExample3:

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 Both wrongExample4:

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 Vertical LookupHLOOKUP Horizontal Lookup

HLOOKUP ExampleExample7: Using HLOOKUP function of excel, find matching departments of the

following instructors:

Example8:

Power Example

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.

Time Between Arrivals (minutes) Probability Cumulative Probability Random-Digit Assignment

1 0.12

2 0.225

5 0.13

7 0.225

8 0.14

9 0.16

Table1. Distribution of time between arrivals

Service Time (minutes) Probability Cumulative Probability Random-Digit Assignment

1 0.1

2 0.2

3 0.3

4 0.25

5 0.1

6 0.05

Table2. Service Time Distribution

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.

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

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

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