Which of the following is NOT typically included in the 'ilities' of a system?

The 'ilities' of a system generally refer to a set of attributes that describe its quality and performance in various operational contexts. These typically encompass key factors such as reliability, maintainability, and availability, which specifically address how well the system functions over time, how easily it can be repaired or updated, and how consistently it can deliver its intended service.

Agility, while an important quality in many modern systems, especially in the context of software development and organizational processes, is not traditionally categorized as one of the 'ilities.' This term often relates more to the ability of a system to respond quickly to changes in environment or requirements rather than a specific measure of operational performance.

In contrast, reliability pertains to the assurance that a system will perform its intended function under stated conditions without failure. Maintainability involves the ease with which a system can be maintained, including repairs and updates, while availability reflects the degree to which a system is operational and accessible when required. Therefore, agility, while valuable, does not fit within the classic definition of 'ilities' as commonly understood in systems engineering.