When you plans are right, but have nothing to do with reality

I’m just starting the book ‘The Guns of August’ by Barbara Tuchman – about the planning and first month of WW I. The most interesting point so far is that the French Plan (Plan #17) took no account of actual intelligence gathered about what the Germans planned. The French basically developed a plan based on current theory and molded what the Germans would do to fit into that theory (‘no way the Germans would march through Belgium and attack out exposed flank…no way…’). Sounds familiar right? developing a plan based on some current theory, regardless of what facts about known…probably a good example that project managers encounter every day is the time required for testing – break/fix. Forget about the last 10 projects that required the same effort to QA/break-fix as what the coding took, let’s assume this time the QA/break-fix effort will only be 25% which is perfect since it will allow us to release the product in time for the big holiday season….yep, planning and execution are truly different when you refuse to take fact into consideration.