The following entrepreneurs use different inventory systems. Based on the information given, can you determine which system they use?

1. Lucille counts the jars of baby food in her warehouse once a month.

2. Lincoln orders a new sofa for his furniture store only after it has been purchased by a customer.

3. Laurie works hard to make sure that she has virtually no inventory in raw materials, work-in-process or finished goods and constantly strives to minimize the time it takes to make her bicycles.

4. LeRoy accounts for each receipt of each new appliance in his store as well as each sale of that appliance as it occurs.

5. Lana loves the new scanning cash registers in her craft shops as she can easily tell the inventory level of each color of thread or yarn she stocks. 

6. Lyndon sells advertising memorabilia online. He checks out the prices of a local store, lists the items at slightly higher prices, and as soon as the order comes in, runs out to buy the item.