This may be due to applications being superseded, more staff joining the company, hardware becoming obsolete etc. Some factors you may want to keep in mind are scalability and availability. Depending on the server you choose, one of the most important decisions is scalability. This is the ability of the server to grow with your company. Scalability can be a very important feature because it means that you can invest in a system with confidence you won't outgrow it.
Many vendors view scalability as the option for a company to scale out and scale up.
Scaling out refers to adding more servers while scaling up means to migrate to more powerful servers. When determining the scalability of a server, there are a number of considerations to keep in mind during this process. Firstly, will the performance of your server be able to stand the test of time. The architecture also determines the overall throughput of the system how quickly data can travel between the various subsystems of a server, and therefore the performance. Keep Moore s Law in mind when making any decision on processors.