You will forget what you did (so document everything)

As engineers we design and analyse things, so we are usually focussed on delivering a result of some kind.

That result needs to be justifiable and repeatable.  That is, at some point in the future someone might ask:

  1. How did you arrive at this result?  What assumptions did you make and what analysis led from there to the result?
  2. What happens to the result if I change one of the inputs?

There is nothing more embarrassing than having to admit that you aren’t exactly sure how you got the result you gave them last time, and that when you do the analysis again now you get a different result.

This is less likely to happen for the big complicated analyses where you are publishing a whole report.  It is much more likely to happen for the quick 5-minute calculations on the back of a fag packet.

Tech Notes are a perfect way to document this stuff, and often the process of writing the note will flush out some extra considerations which you hadn’t thought of.  If you don’t have time for a Tech Note, at least scribble the working down in your lab book or similar.