Category Archives: Production Operations


Has Blockchain Reached its RFID Moment?


Walmart lettuce bag

A good summary by Alexis Bateman and Chris Cottrill of MIT comparing Walmart’s intro of blockchain for leafy greens to their introduction of RFID. As before, they are compelling suppliers to participate.  That gets it done, but does not ensure that there will be a fair division of the benefit.  And of course, it is not clear that there will be benefit.  The technology is still too new.

I’m troubled by the fact that a permanent log of readings from handheld devices may not allow device errors to be corrected.  Some suppliers may be unfairly implicated if reading errors occur. However, if the application only tracks possession and not the presence of disease bacteria, that may not be much of a problem. I suspect that mixing lots from several farmers in a single bag may be a bigger and more contentious legal dilemma.

And it’s not a solution for the little guys. Only a behemoth like Walmart could impose such a requirement.  About as far from the original blockchain concept of decentralization as one can get.

Nonetheless, I’m sure we will learn a lot from the experiment.


via Has Blockchain Reached its RFID Moment?

New Paper in Games

I recently published a new paper in the journal Games.  You can see it below.

It deals with a very important logistics problem. In a cold chain, different parcels require different conditions of temperature. A multiple compartment vehicle can be sued to consolidate loads with different temperature characteristics in one vehicle.   But loading the vehicle at a low cost is a hard problem, requiring heuristics to solve.  And even then, how do we divide the cost of loading among the different package owners in a fair way?  ‘Fair’ here means that no group of owners will choose to leave the consolidation, because they cannot do better on their own than the cost they are charged.

The paper uses an inductive algorithm on top of a common heuristic to give a method for solution. There is a small example in the paper that shows how to apply the algorithm.

games-logovia Games | Free Full-Text | Sharing Loading Costs for Multi Compartment Vehicles

You can get the pdf here.  games-09-00025 (1) final version


Geographic gaps are widening in U.S. as economic growth increases

This is a quite interesting article on the distribution of economic development in the US.  It says we have to start doing something about the ill distribution to a few highly urbanized areas that are often based on high tech industries. 2018-01-25 13-18-03-392   via Geographic gaps are widening while U.S. economic growth increases