I was surprised to hear this the other day where a person was saying how he originally had a person in-line to work on a specific project. But for whatever reason the person has to drop out. My first reaction was to ask what he was going to do now as my assumption was he chose the person specifically because they had some kind of unique skill-set or offering. To my surprise he just had the attitude of he just simply needs to find someone new.
While that seems harsh I guess in many ways it does make sense from a business point of view. You always want the ability to have things running still with a wide variety of people just in case your regulars are unavailable as an example. At the same time just treating people purely like a number seems counterproductive if you are trying to make people feel like they are a part of the company who will stick for the long-term.
If you had to choose one route which one would you go with? I know by the book the proper answer is probably the numbers route but even from my personal experience just as a regular employee companies can get way more productivity from people if they know they are in a sense a huge integral part of the operation.