As CMMI Consultants during CMMI Consulting Assignment, we are often asked the question – What is the difference between Capacity Management and Availability Management mentioned in the Capacity and Availability Management (CAM) Process Area of CMMI for Service version 1.3?

CMMI FAQ 0

10th April, 2015

Although both terms i.e. Capacity and Availability looks similar to process practitioners who has just started the CMMI journey, but in actual these terms have different meaning and focus.

Capacity Management is the management of the total capability or the maximum quantum of work that can be performed because capacity refers to the maximum amount of the work that can be performed or the maximum amount of service that can be delivered. Capacity can be maximum size, maximum volume, or maximum throughput, etc., of a particular entity that it can deliver or perform. Examples of capacity, quoted in the CMMI-SVC Model, include the following:

• Number of vehicles requiring maintenance that can be received on the maintenance premises within a 24-hour period
• Number of loan application forms that can be processed within an 8-hour period
• Size or volume of a disk drive
• Square feet of floor space that can be cleaned per hour
• Number of pounds that a loader can hold at one time
• Total amount of fluid that can be absorbed by a service system component
• Number of calls per day that can be handled by a call center

Availability Management is the management of the quantum of work that is available or that can be done within the maximum amount of work possible. This means within the maximum amount of service that can be delivered, how much can be really delivered is the availability.

Examples of service system components given in the CMMI Model for which availability can be a concern include the following:

• Anesthesia equipment
• Cafeteria staff
• Maintenance supplies
• Transportation components (e.g., cabs, buses, trucks, drivers)
• Call center staff
• Lead appraisers

To summarize, Capacity and Availability Management is the equilibrium between what you can accomplish and what you have available to accomplish at a given point in time and depends on:

• Resources (hardware, software, tools, human skills and competence):
• Need to Deliver Services and their quantum

Source: CMMI-SVC Model, Version 1.3