1 Activate Your Free Trial!  Yawl. Yawl, two-masted sailboat, usually rigged with one or more jibsails, a mainsail, and a mizzen. In common with the ketch, the forward (main) mast is higher than the mizzenmast, but the mizzenmast of a yawl is placed astern of the rudder post, while that of the ketch is closer amidships.
System design is documented in the System Design Document (SDD). It describes design goals set by the project, subsystem decomposition (with UML class diagrams), hardware/software mapping (with UML deployment diagrams), data management, access control, control flow mechanisms, and boundary conditions.
System Requirements Specification (SyRS) : This is the high-level engineering document that enumerates the requirements on how the system is to function. It is not a software-only document; if the system involves hardware, or multiple software components, then it describes them as well.