In IT terms, this means gathering information about business plans, assessing the impact on services and underpinning resources and then buying or upgrading resources (or selling or downgrading resources if demand is falling) in time to avoid either insufficient capacity and missed service levels or excess capacity
and unnecessary cost. For this reason, the capacity management process is sometimes more memorably summarised as ‘Having the right IT capacity in the right place at the right time and at the right cost.’
Without forward planning, achieving this balance is not possible because reacting to capacity shortfalls takes time. It takes time to gain approval to purchase, to physically acquire the capacity and then install and configure it. In the meantime, performance suffers and the business is impacted. Equally, without forward planning, capacity shortfalls may need to be tackled urgently. In such situations, there is a potential for panic buying. It is unlikely that urgent purchases are made in the most cost-effective manner.