[LEAPSECS] Reliability

[Rob Seaman]

Steve Allen wrote:


> On Sun 2009-01-04T20:58:29 -0700, Rob Seaman hath writ:

>> Here's a notion I don't recall seeing before on the list:

>>

>> Coordinate leap seconds with leap days.  Introduce an integral  

>> number of leap seconds each February 29th.  Discuss.

>

> This ignores the existing operational systems, and in particular NTP  

> code.  Any change must be congruent with existing operational  

> systems, and that means nothing more than one second leaps at end of  

> June or December.

>

> It also does not address the underlying problem, which is  

> discontinuity in the broadcast time scale.

>

> I think the "must not adversely affect existing operational systems"  

> clause is an inviolable rule for this process.  It's like the  

> physician's "First, do no harm" rule.

>

> I'd like to think that "makes life better for some parties and not  

> worse for any party" is also paramount in this process.


Brainstorming comes in two phases:  1) generate ideas, and 2) winnow  
them down.  During the first phase, ideas should breed like rabbits.   
During the second phase, they should be matched against clear  
requirements.  Reexamine the requirements and repeat.

Whatever problem solving process we're following here (Monte Carlo  
conceptualization? :-) either we're in a phase of charactering the  
problem space or we're in a phase of characterizing the solution space.

If a problem phase, the discovery of requirements is the goal.  Care  
should be taken to express the essential idea behind each requirement,  
such as (perhaps):
	- change must be congruent with operational systems
	- does "congruent" mean the existence of a viable implementation plan?
	- a mechanism shall exist for managing discontinuities

A requirement that is worded either too specifically or too generally  
will bias the process.

If a solution phase, a quantitative trade-off study is the ultimate  
goal.  Before that can happen, the solution space should be  
extensively explored.  Often, aspects of several different notional  
solutions are combined to form a jointly richer concept.

The part I like most about the February 29th notion is that it  
standardizes all intercalary interactions at a very clearly stated  
moment.  Perhaps this is an aspect that could inform other possible  
solutions.

You'll also note that I didn't specify that this had to be applied to  
UTC.  The first step to implementing brand new technology is to break  
cleanly with the past.

Rob