Monday, December 3, 2012


KISS – Keep It Simple, Stupid 

That’s a well known and widely ignored principle of design in industry.  I don’t know whether it’s as well known in the military but it should be, if it isn’t.  Complex systems look good on paper and, in theory, should perform brilliantly but in reality tend to fail.  Consider a system as a series of events, each with its own probability of failure.  It stands to reason that the fewer steps, the lower the overall probability of failure.  For example, a weapon system that consists of two steps,

  1. detect a target
  2. shoot the target

is less likely to fail than one that performs the exact same task but has many more steps,

  1. detect a target
  2. transfer data to other platforms
  3. consolidate data into common picture
  4. present data to command and control
  5. receive command and control guidance
  6. transfer common picture back to other platforms
  7. select optimum weapons platform
  8. shoot the target

(Sounds a lot like CEC, doesn’t it?  But I digress …)

Under ideal conditions, the more complex system ought to function correctly and may even offer some benefits.  However, factor in the fog of war, jamming, networking problems (they always exist!), incomplete or contradictory data, and so forth, and you have a system that has a much higher probability of failure.  In short, the simplest system that can perform the task is the preferred one.  KISS.  Unfortunately, in peacetime system designers tend to ignore the KISS principle and we wind up with tempermental, failure prone systems that require lots of high-level maintenance. 

Capt. Hughes summed it up nicely while discussing tactics,

“The development of complex tactics is a peacetime predisposition.  After the first battle, tactics are simplified.”
Thus, KISS applies not just to weapon systems but to tactics, doctrine, procedures, and, well, just about everything.

A real life example is Aegis versus conventional radar combat systems, in particular the NTU (New Threat Upgrade) system that was once a viable alternative to Aegis.  NTU with its conventional rotating SPQ-48 and -49 radars would have been (and, indeed, on many ships still is) mechanically simpler, easier to maintain, and potentially repairable at sea in the event of combat damage.  Aegis is currently degraded fleetwide and the Navy has instituted a formal program to bring the system back to spec.  The degradation occurred because the system was too complex for shipboard maintenance or even diagnostics.  It perfectly illustrates the question of whether it’s better to have a simpler system that is operating perfectly or a more complex one that is routinely degraded and unmaintainable.  Now, before anyone writes me and starts telling me about the wonders of Aegis, note that I am illustrating the KISS concept.  I am not suggesting that one or the other system is the better way to go in this particular example.  One would have to be an expert on both systems to make that assessment.

The Navy has had a tendency to try to build highly complex, win-the-war-single-handed systems of late which results in systems that don’t work as advertised.  Consider any of the LCS modules.  They were all far too complex to have a hope of working and now the Navy is scaling them back to much simpler systems that may actually function.  The JSF was intended to be a near-magical platform that would perform astounding feats of aerial dominance – except that the complexity was too great and the program is years overdue and zillions of dollars over budget.  I could go on with examples but you get the idea.

MiG-17 - KISS

You know who had the KISS system mastered?  The Soviets!  Their systems were simple, often mechanical, rugged, easily produced in large quantities, and easy to repair.  Of course, that was partly due to lack of technological expertise as well as a conscious choice.  Still, the lesson of an airplane designed to ingest Foreign Object Debris (FOD) as opposed to the ultra-sensitive US planes is one worth considering.  When combat starts, FOD is going to be a fact of life and it would be nice to have a plane that isn’t affected.

As the Navy moves forward with new designs, especially in this era of budget constraints, they would do well to make KISS the number one design criteria.

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