The IRLE notes that blue collar and manual workers can be replaced for an average cost of $2,000, while the average cost for managerial and professional employees may be as high as $7,000.
By defining a Node * typedef, it is assured that all the variables will be structure pointer types, or say, that each variable is a pointer type pointing to a structure type.
IDEF0 is part of the IDEF family of modeling languages in the field of software engineering, and is built on the functional modeling language Structured Analysis and Design Technique (SADT).