ABSTRACT
Flowcharts have been in use since the early days of computing; as such, they are likely the earliest behavioral model. In the 1960s, vendors often gave away plastic flowchart templates so that programmers could produce neater diagrams. The IBM Corp. even had a standard flowchart template, with varying sizes of the basic symbols. Some old-timers joke that this was the first CASE (computer-aided software engineering) tool.
