Blood Storage

Blood Storage. Blood products at a hospital have a shelf-life. This model demonstrates a way to experiment with the stock of blood as it relates to demand and expiration.

0. This model has one item: Blood Product.

1. Demand Blocks at the end indicate the pull demand. In this case, demand will pull items out of the system rather than push items into the system.

2. Storage is divided into two parts. The Replenishment Pull Block orders more product when the supply gets low. The Queue Block has a maximum number of items and keeps track of how long the products have been in process. When an item has been in process too long, it "balks" to the Exit Block. The total amount in storage is dictated by both the Pull and Queue blocks together.

3. Expired blood moves out of the process. Blood that has spent too long in the process will get moved into this Exit Block using the Balk feature of a Queue Block.

4. When Blood Product is ordered, a batch item will appear here. The Pull Block will determine the number ordered, and then the items will begin the delivery process.

5. Unbatch all in this queue to inspect individually. The Queue Block has a setting to "Unbatch All," which takes a batch item and turns it into an individual item.

Combining the Pull Block and Queue Block is an effective way to model ordering new supply and expiring old supply. Experiment with the amount of inventory needed to match demand and show what adjustments to make if demand fluctuates.