Rates and Buffers
Last updated
Last updated
Now, we can set up the rates for the constraints and capacities for the remaining buffers. Within the constraints configuration, you can also access information about interrupts. We will cover the interrupts portion in the next page.
From the video, we know 2 rates:
Each molding machine is capable of producing 5,000 cookies per hour
The packaging line is capable of processing 3,000 assembled cookies per minute
To keep this example simple, we will set all constraints in the baking lines and packaging line to those rates converted to correct units, respectively.
For the baking lines, we will need to first convert the hourly rate into a rate per minute. 5,000/60 = 83.333 cookies per minute. We will round this up to 84 cookies per minute for simplicity. All constraints from "Molding" to "Cream Pump" on both baking lines will receive this rate.
If you Interrupts appear differently at this stage, do not worry. We will adjust these in the next step.
In order for the mixers to process enough ingredient mix for 84 cookies per minute, they must consume 84 x 0.008811 = 0.74 pounds of ingredient mix per minute. We will round this up to 0.75 pounds per minute.
The assembly constraints need a rate of 0.5 x 84 = 42 full cookies per minute to keep up since each assembled cookie consumes two cookies.
Finally, all of the packaging steps will receive a rate of 3,000/36 = 83.333 packages per minute, which we will also round up to 84.
Next, we will handle the buffers. We have already taken care of the initial buffer in a previous step, so the first buffer we are concerned with is for baked cookies. Recall that these lines are producing cookies at a rate of approximately 5,000 per hour. We will set up a 4 hour buffer of 20,000 cookies on both lines.
The next buffer we have to worry about is for the assembled cookies after the baking lines merge. Combined, both baking lines are producing assembled cookies at a rate of approximately 5,000 per hour. Again, we will set up a 4 hour buffer of 20,000 assembled cookies.
The final buffer is for finished product. We want to make sure this one has infinite capacity to capture the full production during the simulation.
It is easiest to edit all of the buffers at once from the "Buffers" dropdown in the nav bar:
