Capacity planning is a process to help plan for an organization's future. Capacity planning is for determining the best way to complete business requirements such as increases in the amount of work to be done, while at the same time meeting service level requirements.

"The basic steps involved in developing a capacity plan are:

1. To determine service level requirements

a. Define workloads

b. Determine the unit of work

c. Identify service levels for each workload

2. To analyze current system capacity

a. Measure service levels and compare to objectives

b. Measure overall resource usage

c. Measure resource usage by workload

d. Identify components of response time

3. To plan for the future

a. Determine future processing requirements

b. Plan future system configuration

By following these steps, we can help to ensure that your organization will be prepared for the future, ensuring that service level requirements will be met using an optimal configuration.

A good capacity management plan is based on monitoring and measuring load data over time and implementing flexible solutions to handle variances without impacting performance."

http://blogs.hexaware.com/quality-assurance-and-testing-services/capacit...