Tree swing cartoon

A tree swing cartoon or tire swing cartoon is a humorous graphical metaphor that purports to explain communication pitfalls in the division of labor in the development of a product. It depicts how different departments implement or describe a tire swing attached to a tree, and how different it is from what the customer actually intended. It has also been used to illustrate the waterfall model of software development.
The original version appears to be from the early 1970s, possibly 1973. Many variants of it appeared later in several books on education, software engineering and management.