The main task of Capacity Management is to draw up the Capacity Plan.
The Capacity Plan includes:
- All the information about the capacity of the IT infrastructure.
- Forecasts of future needs based on trends, business forecasts and existing SLAs.
- The changes needed to adapt the IT capacity to technological changes and the emerging needs of users and customers.
The Capacity Plan must include information about the costs of current and forecast capacity. This information is essential in order for financial management to be able to prepare budgets and make financial forecasts realistically.
Although, in principle, the Capacity Plan may be for a period of one or two years, it is important to monitor compliance so as to adopt corrective measures as soon as any important deviations are detected.
Modelling and Benchmarking
The more complex the IT infrastructure, the more difficult it is to forecast future capacity needs. This makes it essential to use models and simulations of possible scenarios for future developments so as to ensure hardware and applications are properly scalable.
The level of detail to which this modelling is taken will depend on several factors:
- Costs associated with the increase in capacity.
- Costs inherent in the process of modelling and simulation itself.
- Scope of the envisaged capacity increases.
- The "criticality" of the systems involved.
Weighing up these factors we can opt for:
- A simple analysis of trends which allows the process load on the IT infrastructure to be assessed and the current capacity scaled accordingly.
- modelling and simulating various different scenarios in order to make load forecasts and predict the response of the IT infrastructure.
- Benchmarking real prototypes to ensure the capacity and performance of the future infrastructure.