Phase 2. Configure and Run Variation Experiment
In the previous
phase we imported the scenario and examined the statistics with the
data gathered by the Simulation experiment. In this phase we will set
up and run the variation experiment to define the optimal parameters of
the Inventory policy.
Create and configure Variation
Now we will define the variable parameters, which represent the data
the experiment will work with. In our case we will vary the Min and Max
parameters of the inventory policy.
to the Experiments
section and select Variation experiment. You will be taken to the Variation
experiment's view with its default settings.
- Leave the Experiment duration
parameter as it is.
- Click the Use replications
toggle button and specify 3 in the Replications
per iteration field.
We need replications since demand of the Boston
customer is set to
The model will have stochastic behavior resulting in a less
representative experiment run. To improve representability we will
enable replications, which will result in conducting several runs per
each iteration. Keep in mind that it takes a bit more
complete the experiment if replications are enabled.
variable parameter that you define is set for a single parameter only.
If you need to
vary several parameters during the experiment, you need to create a
separate variation for each parameter.
We have completed setting up the Variation experiment and may run
- Click Add
beneath the Variable parameters
to open a dialog box with the scenario's parameters that you
- Define variation of the min
parameter as shown on the
screenshot below. Click OK
close the dialog box.
In the same way create variation of the
parameter and set its Min
and Max values to 2000
and 5000 respectively.
There, we have defined two variable parameters of the
to open the dialog box allowing you to
select, configure the required statistics and define the measurement
units to be used in the statistics.
Click the Product
statistics unit drop-down list and select pcs, since it is the product
measurement unit defined in the Products
- Enable the Lost orders
- Type Lost orders
in the Name column
filter field. Press Enter. The result of the search will return the
- Click the toggle button to the left of it in the Enabled column to activate
collection for these statistics.
- In the same way check the Total
It should be enabled by default.
- When done, remove the filter by clicking the icon to the
right of the statistics name and type true
in the Enabled filter field
to see all the enabled statistics.
- Click OK to
close the Configure
statistics dialog box.
A table will appear updating its records with
received real-time. Experiment execution will take some time.
Perform sequential sorting of the data based on the Lost orders column to instantly see
the best currently available result:
- Click the Lost orders
column title to sort the records in the ascending order.
- Press and hold the Alt
key, then click on the title of the Total
- Observe the final results. When the experiment is
completed, you will be taken to the Variation
results tab of the new Result
item of the Variation experiment
branch, containing the results. Sort the data in the
way as you did after starting the experiment.
As you can see there is just one successful result, which is
the top one. According to it, if the Min
values of the Inventory policy parameters are set to 1,901
and 4,900 respectively, we will not lose a
order and we will incur the total expenses of $172,480,736.311,
which is a bit more than the initial amount, but it is the price we
have to pay to maintain high quality of delivery service.
You can navigate to the Inventory
table and update the parameters of the defined policy with the acquired
results can be improved by adjusting the variable parameters for the
Basing on the value range that we specified for the two
variables, the experiment suggests the Min and Max
values to be set to 1,901 and 4,900
respectively. Now that we know these Min
and Max values we may
adjust the variable parameters by altering the range of the
variables and the step of variation to receive a more precise result.
Adjust the variable
The received result can be adjusted again to provide even more precise
inventory policy parameters. You can:
- Select the first variable and click Edit
below the Variable parameters
box to open.
- Change the Min
and Max values to 1,500
and 2,500 respectively.
- Set Step to 50.
- Click OK to
close the dialog
- In the same way adjust the second variable by changing
its Min and Max
values to 4,500 and 5,500
respectively, and setting Step
- Run the Variation experiment and examine the final
which will be located in Result
1 item of the Variation
Compare the received results with the results
from the Result item
of the Variation
experiment branch. You will see that the Min and Max
inventory policy parameters differ and the incurred
less this time, but we still have managed to satisfy our
You can navigate to the Inventory
table and update the parameters of the defined policy type with the
- Decrease the specified range for each variable parameter
(e.g. Min - 1800-2200, Max - 4800-5200).
- Decrease the step size from 50 to 25, 10 or 5 (the
the step is, the more time is needed to complete the experiment).
- Increase the quantity of replications to 5-10 (the more
replication per iteration, the more time is needed to complete the
We have successfully completed the Variation experiment tutorial.
1. Import scenario and examine statistics