Clicking the OK button on the Initial Conditions dialog
opens the PNG worksheet where the game is played. The figure
below shows the worksheet as it first appears. The dialog at
the upper left holds the step or week number, the current cost
and the production change field labeled "Prod. Chg.".
The Step is
the current week. The Total Cost is the sum of all costs
expended from week 1 to the current week.
The simulation starts
at the beginning of week 2. The data for week 1 is shown in
the row labeled 1. The beginning inventory of week 1 is set
as an initial condition. The demand for week 1 is randomly
generated from a normal distribution with mean 100 and standard
deviation 30. The first week's demand is 97 for the example.
The production in week 1 is set as an initial condition and
is 70 for the example. The ending inventory
is the beginning inventory plus the production minus the demand.
Shortages are backordered and a shortage condition is indicated
by a negative value for inventory.
Only the production change field is controlled
by the user. In the example, we choose 0 as the production change.
If a nonzero value with magnitude greater than 5 is entered,
the production change occurs two weeks later. A number greater
than 10 may be entered, but the production change is limited
The Next button
leads to the next week. The Quit button closes the