Hello friends, in this article, we will learn how to observe in the easiest way how the different scenarios in the simulation models we created affects the performance criteria we set.
Process Analyzer tool of Arena Simulation software will help us in this regard. First, let’s talk about an example scenario where we can use this tool. Afterwards, we will reinforce our knowledge by practicing.
Let’s say we will create a simulation model of a cafeteria business. This business has an existing work flow. The business owner wants to make improvements on different scenarios, but cannot determine which scenario will provide the maximum benefit clearly. Now let’s take a closer look at the current state of the system.
The time between the arrival of the students in the cafeteria is TRIA (1,2,3) minutes. There are three different sections in the cafeteria;
- Fast Food
- Home-cooked
- Beverages and snacks
60% of the students who come to the cafeteria go to the fast food section, 30% go to the home-cooked section and the rest go directly to the beverage and snack section.
While 90% of the students who go to the fast food section, after, go to the beverages and snacks section, 75% of the students who go to the home-cooked section, also, proceed to this section after they have their meals.
Students who meet their needs go to the sitting area after making their payments in the cash register.
There are 2 staff working in the fast food department and they perfom simultaneously to meet the needs of each student. 2 staff prepare a student’s order in NORM(1,3) minutes.
There are 3 staff working in the home-cooked department and all of the staff prepare the food order of a student at the same time in UNIF (1,5) minutes.
In the beverages and snacks department, only one staff is working and the processing time each student spends in this department is TRIA(1,2,4) minutes.
In the cash desk, the average time spent is NORM(2,6) minutes and there is 1 cashier working in this section.
The goal of the business is to minimize the time students spend in the system. All personnel, except the cashier, can perform each other’s duties in the cafeteria.
Many scenarios run through the mind of the business owner. Details of these scenarios are available in the table below.
Now we will create our simulation model together and we will determine the best scenario using the Process Analyzer tool through this model.
After creating our simulation model, we select the process analyzer option from the tools section (Picture 1).
When we create a new file here, an empty table appears (Picture 2). We add new scenarios by double-clicking on this table. While adding the scenario, we select the file of the simulation model we created with the file type “.p” (Picture 3).
After creating 6 different rows in the same way, we add controls by right-clicking on the table (Picture 4).
We come across variables that we can control in our simulation model , and here we select the criteria we want to control (Picture 5). In our example, we choose “the resources” because we want to control the number of employees.
After adding the control values, we add the average time spent by the students in the system, which is our performance criterion, as a new column (Picture 6, Picture 7).
The final state of our table is as in Picture 8.
Here, we write our scenarios in the fields of the values we want to control. After writing the scenarios, the state of our table will be as in Picture 9.
We select all our lines by dragging and press the start button on the top bar (Picture 10).
Process analyzer tool will run our model for each scenario and show us the value of our performance criteria.
Our analysis result will be as in Picture 11.
When we analyze the result for the best scenario;
We see that 3 person should work in the fast food section, 1 person in the home-cooked section and 2 person in the beverage and snack section. In this scenario, the time spent by the students in the cafeteria was determined as 0.193 hour.
With this article, we observed the effects of different scenarios on our performance criteria through a single simulation model. We used the Process Analyzer tool while performing this task. I hope it will be useful for your work. See you in the next article, regards.