Comments on: Why FIFO: The Benefits of First In, First Out

By: Julia Newell

Julia Newell — Wed, 12 Oct 2022 16:03:28 +0000

Hi Christoph, I really enjoyed your post. It is crucial for manufacturers to emphasize FIFO in their daily operations. Without it, as you mentioned in another comment, LIFO can come across and increase lead times. In my personal experience, I’ve found that misplaced items that aren’t accounted for inventory can cause LIFO. It is important to keep an organized and effective storeroom to make this possible.

By: Christoph Roser

Christoph Roser — Thu, 06 Oct 2022 09:50:34 +0000

Hello Cornelio, a normal distribution is a bad approximation for process times, because normal distributions start at negative infinity. Even ignoring that, distribution of process times are often very one sided (it can take quite a bit longer, but is unlikely to be much faster than the median). A Pearson distribution would be better here, but I simplified a bit in my simulation. I believe the results would be somewhat comparable to the exponential distribution I used.

By: Cornelio Abellanas

Cornelio Abellanas — Thu, 06 Oct 2022 09:31:01 +0000

I can understand that interarrival times typically follow an exponential distribution but I would expect process times to be closer to normal.

By: Christoph Roser

Christoph Roser — Wed, 05 Oct 2022 09:53:02 +0000

Hi Emily, LIFO is usually not a choice, but either an accident or through storage design (e.g. a coal pile is both added and removed from the top).

By: Emily Pires

Emily Pires — Tue, 04 Oct 2022 19:38:24 +0000

This is a great post and really points out many of the benefits of using FIFO and why it makes so much more sense than using LIFO. I liked how you provided graphs that explained the misconception they show with LIFO versus FIFO. It seems LIFO if much more difficult to plan lead times and buffer inventory with. FIFO is much more clearly defined and more efficient, like you said. Traceability seems like a very important reason why FIFO is better, especially when thinking about defects. I wonder what type of companies would use LIFO and what their reasoning would be for choosing that over FIFO?