- MUST ~ REQUIRED ~ SHALL - Is an absolute requirement.
- SHOULD ~ RECOMMENDED - It is strongly suggested to follow the instructions, but deviation is not excluded, if there is a reason.
- MAY ~ CAN ~ OPTIONAL - System is furthermore interoperable, if an optional item is missed
Wednesday, July 1, 2009
Constantly used Key Words to indicate Requirement Levels
During the analyze and design of a product, Business Champions and Architects use some words (Key Words) to indicate some requirement levels in specification. Their meaning is well-defined by the memo of S. Bradner, Key Words for use in RFCs to Indicate Requirement Levels. But here is a summary: