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Building Accurate Shipment Timelines – A Sorted Affair

100 points by rottencupcakes 9y ago

cconsidine 9y ago
A+ technical gifs
sghiassy 9y ago
Nice article Will any software be open sourced related to this?
- dmnd 9y ago
  As far as I know we don't intend to release anything. But if you have a similar timeline ordering problem, the post should contain enough detail for you to apply the ideas.
- tdb7893 9y ago
  It sounds mainly like a pretty basic topological sort applied in an clever way. You probably could find pseudocode for the basic algorithm on Wikipedia.
  - egillie 9y ago
    You can! https://en.wikipedia.org/wiki/Topological_sorting#Kahn.27s_algorithm https://en.wikipedia.org/wiki/Topological_sorting#Kahn.27s_a...
aubreycw 9y ago
Author here! This was the first post of our new Flexport Engineering blog (we'll be adding more content soon). Happy to answer any questions about the article or how/why we're using kahn's algorithm.
- MrBuddyCasino 9y ago
  Thanks for the article, this would have been helpful to me some time ago. I found out the hard way that data quality in logistics is generally quite poor.
- zodiac 9y ago
  I'm curious what the intransitive example (with A > B, B > C, C > A) was exactly
  - aubreycw 9y ago
    I think the section talking about that was phrased a little weirdly. It was meant to express that we decided to assume transitivity unless we could find a counterexample, and that we haven't yet found one. I've updated the wording a bit to have it be clearer now!
siscia 9y ago
Hi, I would like to share an idea i had a while back with you flexport folks. I work in an IoT company that focus on the hardware side, while I am the one responsable for having the software running smooth. Chatting about the new hardware piece that were coming my first though was the following. Have a very small piece of hardware, transmitter, to ship along whatever you are shipping. The transmitter will regularly (even every 5 minutes) transmit its position so that would be possible to track the geographical coordinates of every lot of product that is shipped. The difficult part is that the transmitter need a receiver (with Internet connectivity) in close range ~10km, the solution would be to install those receiver in the ship or in the truck or in the train. The hardware itself is something that we are using every day and it is not a big issue, the only real problem that I see is the installation of those receivers. Is this something worth solving?
- xyzzy_plugh 9y ago
  Traditionally there are a lot of issues (battery vs. broadcast power vs. non-transmissive material (like fluids)), and it doesn't replace the need for old fashioned inventory management. At best it supplements it, and in a margins game the advantage just doesn't materialize into monetary savings. You do see similar technologies in some situations (RFID), but solving the general opaque shipping problem is surprisingly tricky.
- shouldbworking 9y ago
  This exists where the economics make the most sense. Some shipping containers have built in tracking and satellite links. Usually the ones with expensive or refrigerated stuff.
  - egillie 9y ago
    Exactly. Some shipments even have pallet-level tracking if the products are expensive enough to justify it.
- wtracy 9y ago
  From what I've seen of this industry, there's two major hurdles to getting this working: One, getting the shipping companies to provide any kind of network infrastructure would be like pulling teeth, and two, a lot of the companies doing this shipping are running on margins so tight that they care about things like saving 25 cents on a box. Their idea of cheap is completely different from yours. I'm interested in solving a slightly different issue: could you build a cheap device that records accelerometer data while an item is in transit, to create a record of which way a box was oriented, and how hard it was dropped? Maybe provide a USB interface to download the data on arrival? Something like that would be interesting to businesses that ship fragile, high-value items and want evidence to back up the claim that items were damaged in transit. (I'm thinking of things like television sets.)

cconsidine 9y ago

A+ technical gifs

sghiassy 9y ago

Nice article Will any software be open sourced related to this?

dmnd 9y ago
As far as I know we don't intend to release anything. But if you have a similar timeline ordering problem, the post should contain enough detail for you to apply the ideas.
tdb7893 9y ago
It sounds mainly like a pretty basic topological sort applied in an clever way. You probably could find pseudocode for the basic algorithm on Wikipedia.
- egillie 9y ago
  You can! https://en.wikipedia.org/wiki/Topological_sorting#Kahn.27s_algorithm https://en.wikipedia.org/wiki/Topological_sorting#Kahn.27s_a...

aubreycw 9y ago

Author here! This was the first post of our new Flexport Engineering blog (we'll be adding more content soon). Happy to answer any questions about the article or how/why we're using kahn's algorithm.

MrBuddyCasino 9y ago
Thanks for the article, this would have been helpful to me some time ago. I found out the hard way that data quality in logistics is generally quite poor.
zodiac 9y ago
I'm curious what the intransitive example (with A > B, B > C, C > A) was exactly
- aubreycw 9y ago
  I think the section talking about that was phrased a little weirdly. It was meant to express that we decided to assume transitivity unless we could find a counterexample, and that we haven't yet found one. I've updated the wording a bit to have it be clearer now!

siscia 9y ago

Hi, I would like to share an idea i had a while back with you flexport folks. I work in an IoT company that focus on the hardware side, while I am the one responsable for having the software running smooth. Chatting about the new hardware piece that were coming my first though was the following. Have a very small piece of hardware, transmitter, to ship along whatever you are shipping. The transmitter will regularly (even every 5 minutes) transmit its position so that would be possible to track the geographical coordinates of every lot of product that is shipped. The difficult part is that the transmitter need a receiver (with Internet connectivity) in close range ~10km, the solution would be to install those receiver in the ship or in the truck or in the train. The hardware itself is something that we are using every day and it is not a big issue, the only real problem that I see is the installation of those receivers. Is this something worth solving?

xyzzy_plugh 9y ago
Traditionally there are a lot of issues (battery vs. broadcast power vs. non-transmissive material (like fluids)), and it doesn't replace the need for old fashioned inventory management. At best it supplements it, and in a margins game the advantage just doesn't materialize into monetary savings. You do see similar technologies in some situations (RFID), but solving the general opaque shipping problem is surprisingly tricky.
shouldbworking 9y ago
This exists where the economics make the most sense. Some shipping containers have built in tracking and satellite links. Usually the ones with expensive or refrigerated stuff.
- egillie 9y ago
  Exactly. Some shipments even have pallet-level tracking if the products are expensive enough to justify it.
wtracy 9y ago
From what I've seen of this industry, there's two major hurdles to getting this working: One, getting the shipping companies to provide any kind of network infrastructure would be like pulling teeth, and two, a lot of the companies doing this shipping are running on margins so tight that they care about things like saving 25 cents on a box. Their idea of cheap is completely different from yours. I'm interested in solving a slightly different issue: could you build a cheap device that records accelerometer data while an item is in transit, to create a record of which way a box was oriented, and how hard it was dropped? Maybe provide a USB interface to download the data on arrival? Something like that would be interesting to businesses that ship fragile, high-value items and want evidence to back up the claim that items were damaged in transit. (I'm thinking of things like television sets.)