Here it is, free for nothin' and worth every cent:
When you are asked to help on a project in which your employer has three (3) days of on-site help (and not one second more) from the supplier, a project in which your immediate boss and his department head had determined and specified every functionality they need weeks in advance, do not go to some effort to trip up the implementation of those functions while lecturing all around you about how that sort of thing is unnecessary, always causes trouble and, based on your Decades of Experience in The Business (within +/- 5 years of everyone else working with you, buddy), Must Not Be Done. Especially do not when earlier versions of most of the stuff you're warning against were already in use for at least twenty years and have been much-missed by the operating staff in the two and a half years after being removed.
That would be the same operating staff that looks at you, aghast, as you deliver your pronouncements about How Things Are To Be Done, even though you have never done any of them yourself.
And really don't do it when your boss is standin' behind you, listening. 'Cos it took me a lot of work to get him in the right place at the right time.
That is all.
2 weeks ago