Cold Enough?

 It was quite the week in North Texas last week.  Two snow falls, temperatures well below freezing, power outages and burst pipes.  We hearing about the "historic" nature of the weather last week.  Anyone familiar with the North Texas climate would consider this picture as "unseasonable".  We were lucky.  Our power did not fail.  Our old house did reveal some serious drafts especially when the temperature dropped below 0 degrees F.  With closed doors we were able to keep a few rooms relatively comfortable.  Overall the house was warm enough to avoid frozen and burst pipes.  The week was still very stressful.  You could not let your guard down, constantly checking pipes to make sure they were dripping to keep them from freezing.  Always remembering to keep the cupboard doors open under sinks to let warm air in and around pipes.  We did lose internet access for about 20 hours.

I did get out and shovel the snow a couple of days and I did find being out in the crisp air refreshing.

In between the worry and the crisp air I did find time to wonder why things went so wrong.  The weather was unusual but hardly historic.  This kind of weather has occurred before in this area.  The biggest issue was the lack of electrical power in the state.  As we have all heard Texas has its own power grid.  There are 3 power grids in the US East, West and Texas.  Neither of the 3 are perfect.  I was in the North east in 2003 when a software glitch and overgrown trees in Ohio caused an outage across several states and Canada.  This summer the west coast had to issue rolling black outs to avoid a total system failure.  So nothing is perfect.

The progression of events is really quite straight forward.  The temperature dropped many components of the power grids production froze.  Production of electricity fell by 40% (that's right almost half).  To avoid a total disaster the power companies instituted rolling blackouts.  Rolling blackouts did not "roll" very well.  Without adequate power people could not heat their houses.  No heat meant frozen and burst pipes.  Water treatment plants without power could not run pumps and so people had to boil water.  Boiling water without electricity can be a challenge.

Back up; the the power grid production froze?  How did that happen?

I have been hard pressed to explain micro exploitation.  I hope this can clarify it and help apply it to the situation in Texas during the storm.  Back in my manufacturing days I remember a unit we built for automatic transmissions.  To break it down it had 3 main components.  It had a plastic valve body and glass stopper that sat inside the the valve and a actuator that sat on the glass stopper.  My department made the valve body, the glass stopper ( it was actually a bead) was purchased and the actuator was fashioned on a cnc machine in the metal shop.  Each of these items was manufactured to a designed size and tolerance.  So for example:

Valve body            0.50 inch    +/-    0.01 inch

glass bead             0.20 inch    +/-    0.005 inch 

Actuator                0.75 inch    +/-    0.01 inch

When the unit was assembled with each stacked on top of the other.  Body then glass stopper then actuator the over all length was 0.50 + 0.20 + 0.75 = 1.45 inches.  The assembled unit was also designed to a specified size and tolerance.  It would have been 1.45 inch +/-0.015.

What happens however if the three parts are built within designed tolerances but on the low end?  So for example the actual sizes were

Valve body                0.49 inch

glass bead                 0.195 inch

actuator                    0.74 inch  

When these 3 items are assembled the over all size would be 0.49+0.195+0.74=1.425 inch.  This assembled item would not produce an acceptable unit since it falls outside the tolerance range of 1.45 in +/- 0.015 (1.60 inches - 1.30 inches).  All individual parts are within tolerances but the built unit is not.  This is how I look at the concept of micro exploitation.  No one component was "wrong" but the overall affect produces an undesirable result.  In the example above I made a point of the fact that each of the 3 different components were source from different places.  The same thought could be applied to a multistep process where each step is performed by a different entity.  Each step is maximized in isolation without any understanding of subsequent steps.

The power failed in Texas due to a number of reasons and I am sure that one of the steps will bear the brunt of the blame.  However if we dig deeper it will prove to be more of a failure of a multi step process.  Almost like the left hand not knowing what the right hand is doing.