Separated at birth
Capacity Management ensures there is enough capacity in the infrastructure to meet the current and future requirements of the business. Capacity management exists to play a balancing act (read optimizing), the goal is to prevent both – under-provision and over-provision of capacities, to have just about enough capacity to meet the current service levels and future business requirements whilst keeping the cost in check.
If you own two cars you cannot let one car run with no spare tyres while the other car has four spares.
The objective of performance management is to identify ‘performance bottlenecks’ and remove them. More often than not, it boils down to capacity issues, increase the capacity and the bottleneck is removed.
Continuing from the previous example, both cars are identical and have the same horse power rating but one can easily do 90 mph on the highway while the other struggles to touch 85, you later discover that the slower car didn’t have enough air pressure in the tyres which prevented the car from reaching higher speeds. You fill the air and the cars perform at an equal level now.
Performance management, by using monitoring tools observes performance issues, analyses and finds ‘performance bottlenecks’ and highlights them, capacity management then liaises with the business (highlights the risks involved) to get approval to provision extra capacity, capacity management also coordinates with change management to schedule the capacity enhancement *change* making sure the change is tested and verified before being implemented.
It is performance management which again provides inputs on the change to capacity management
And they lived happily ever after……
The systems are performing as desired, meeting the service levels month on month, there are no issues, it all looks hunky dory. The business decides they need to enhance the functionality of the system.An important questions arises – will the existing system continue to work as smoothly with the enhancement?
Hop in the twin sisters to reassure the business that the enhancement worked as desired in their simulations (performance mgmt.) and that the enhancement will not require additional resources (capacity mgmt.) and can work with the existing infrastructure.