A value stream is a series of steps or activities that an organization undertakes to deliver value to a customer, starting from the initial request to the final delivery of a product or service. It represents the end-to-end flow of value and includes all tasks necessary for the creation and delivery of the product or service, regardless of whether they are performed by development teams, operations, or other departments.

Option Analysis:

A . Incorrect. While agility involves doing something as and when needed, this doesn't define a value stream.

B . Partially correct but too narrow. A value stream encompasses more than just development and deployment; it includes all activities related to delivering customer value.

C . Correct. This encapsulates the end-to-end activities from customer request to delivery, which aligns with the value stream concept in Lean and Agile practices.

D . Incorrect. This defines 'value' in IT services, not the concept of a value stream.

Lean Thinking by James P. Womack and Daniel T. Jones

SAFe Framework: Understanding Value Streams

ITIL 4: Managing Professional - High-Velocity IT, which includes value streams as part of ITSM evolution.