All corrections
Wikipedia July 7, 2026 at 05:12 AM

en.wikipedia.org/wiki/Critical_path_method

1 correction found

1
Claim
CPM was used for the first time in 1966 for the major skyscraper development of constructing the former World Trade Center Twin Towers in New York City.
Correction

This is incorrect: documented CPM development and real-world testing predate 1966 by several years, and the method was publicly presented in 1959.

Full reasoning

Primary historical sources on CPM place its development and first real-world use in the 1956–1959 period, not 1966.

The most direct source is the PMI history written by CPM co-developers James E. Kelley Jr. and Morgan R. Walker. They state that CPM "evolved" from work beginning in December 1956, describe the process for first testing CPM, and recount that the development effort included a "first live test" before the method was presented publicly. In the same account, they write that "In March 1959, CPM was presented to the public at large."

That directly contradicts the article's statement that CPM was "used for the first time" in 1966 for the World Trade Center. By 1966, CPM had already been developed, tested, and described in public literature for years.

A second PMI historical overview independently confirms this chronology, noting that Kelley was already working on related scheduling problems in 1957 and that he and Walker presented the first article on critical path project scheduling in 1959.

So while CPM may well have been used on the World Trade Center project, it was not the first time the method was used.

2 sources
Model: OPENAI_GPT_5 Prompt: v1.16.0