Steel Thread

Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. A steel thread is a software engineering construct that indicates the most important path(s) of execution in a computer system. The focus is on core usage or basic behavior of the system. Little regard is given to exception logic or other functionality that is not fundamental to the system's nature. Most often, the steel thread is stated in the context of a use case and represented by a sequence diagram in UML. The term is derived from the idea that the system's primary functionality is a "thread" that runs throughout the system, and that this thread's importance makes it strong, like "steel". "Thread" in this context should be analogized to a string in a piece of cloth, not a thread of execution that is more commonly referred to in discussions on computer systems.