Back story - I was hired by my current employer out of college as a web developer roughly 2 years ago. In that two years, I have taken on some of the roles of a system administrator as this position was non-existent before I started and we've now grown to 65 local/remote users. I've replaced much of the outdated server hardware and software that was causing a bottleneck within the organization, and implemented some policies (both server and user) to cope with much of the issues that were effecting the companies IT infrastructure. Much thanks to the SuperUser, StackOverflow and Severfault communities, by the way.
Anyways, Flash forward to today - We're hiring 4 more people and we need 4 new computers. I was hoping to purchase 65 new computers in the Summer of 2011 as our current machines are over 4 years old, and this is when the budget will allow me to do so. How common are company wide computer replacement policies?
I was hoping to implement a "replacement policy" whereby we will replace all machines after x years and buy identical machines for each user (as no special computer accommodations need to be made for our users).
I suppose my question is, how do I implement an efficient/effective computer replacement policy to provide a uniform software/hardware user experience, while dealing with my current need to purchase 4 machines? Do I set a standard for our computers now and follow it when purchasing for the next x years? What works, What doesn't, What do you folks think?