A workflow process of measuring current usage, utilization, and growth rate over time, stirring these three ingredients together, and extrapolating a plan to accomidate future business growth based on future usage and utilization (capacity) projections.

Capacity planning is usually done in the form of written technical reccomendations, and usually follow up with gear quotations and dollar ammounts ($) that you can give your boss to answer questions such as "what will we need 6 months from now to sustain normal operation of my business? 12 months from now? 24 months from now?"