Why the 95:5 is wrong…

Why the 95:5 is wrong… or at least annoyingly over-simplified and misleading. (Ooh, contentious!) I was engaged in a conversation with a colleague earlier this week which resulted in a discussion on the merits or otherwise of the much-quoted β€œ95:5” concept. That is, that 95% of performance is supposedly caused by the system, and 5%…