Redundancy’s Redundancy

How could Boeing decide to build a system based on the data of a single sensor, when it was from Boeing’s kind — from engineers — that we learned the value of redundancy in legal systems?


While most airplane systems are built with backup redundancies to prevent a single data malfunction from altering a plane’s course, MCAS is triggered by data from just one angle of attack sensor, not two.

Hadra Ahmed et al., Ethiopian Crash Investigators Call for Inquiry Into Boeing Max Controls, N.Y. Times, March 4, 2019.


The [judicial system has] the structural characteristic of forum or jurisdictional redundancy. This characteristic of redundancy in the design of other sorts of systems is now well understood to be essential to secure reliability. Everyone understands that if you wish to make sure that a physical structure is strong enough at certain points you put extra material or extra strong material at the given point. Or you may duplicate the critical beam or arch, using two components where one might do. Fairly early in the development of cybernetics as a separate discipline, it was also demonstrated that redundancy could provide a solution in principle to the problem of unreliability of components in information systems. Since that time, sophisticated refinements in specification of necessary redundancy characteristics in information systems have been made. . . . [The utility of redundancy justifies] the jurisdictional redundancy which characterizes our federalism.

Robert M. Cover, The Uses of Jurisdictional Redundancy: Interest, Ideology, and Innovation, 22 Wm. & Mary L. Rev. 639, 649 (1981).