Sunday, June 26, 2016

Estimates are bad (and I mean it!)

Recently I wrote about my belief that it is a good thing to estimate. After all thats one of the differentiators that distinguishes us from other forms of life on this planet.

There is a huge number of quotes one can draw from to see the difference:

“Plans are nothing, planning is everything”

-- D. Eisenhower (maybe)

“In preparing for battle I found that Plans are almost useless, but planning is indispensable”

-- perhaps D. Eisenhower or Moltke

“No plan ever survives the first contact with the enemy, but no one survives the first contact with the enemy without a plan”

-- probably Moltke or Clausewitz

It's not so easy to find out who really is the originator of each quote – and I haven't found one yet from Sun Tsu, although I am sure there is one. But the important thing is that all those quotes make a very clear distinction between the act of planning and the actual plan. And there seems to be a common understanding, that the activity is important while the artifact itself –“The Plan”– is very brittle. And has to be adjusted accordingly. Often.

In my experience the same is true for estimates: don't hesitate to adjust them to adapt to a changing situation, but gather enough information and do enough planning to start with estimates that seem plausible to yourself.

Think about harvest planning in the middle ages – having leftovers at the end of winter didn't kill villages, stretching the food for the second half of the winter didn't kill villages. Not knowing how much demand for food there is and living in splendor until Christmas would have been disastrous.

So here the art of the possible would be to do “just enough” estimation.

How much effort would that be? :-)

till next time
  Michael Mahlberg

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