Page "Extreme programming" Paragraph 5

Other authors have tried to reconcile XP with the older methods in order to form a unified method.

Some of these XP sought to replace, such as the waterfall method ; example: Project Lifecycles: Waterfall, Rapid Application Development, and All That.

JPMorgan Chase & Co. tried combining XP with the computer programming methods of Capability Maturity Model Integration ( CMMI ), and Six Sigma.

They found that the three systems reinforced each other well, leading to better development, and did not mutually contradict.