Back in the HEAT for Windows days the only SDLC methodologies that were on the HEAT radar and considered “the norm” were Waterfall and Iterative, and there was little to no discussion about SDLC.
In 2001 Agile entered the stage Lean followed soon thereafter in 2003, and in 2008 DevOps entered the stage. Depending on who you ask, the majority of software development is still Agile, some Lean, and DevOps is the latest contender.
Meanwhile, HEAT for ITSM emerged, was acquired by Ivanti, rebranded Ivanti Service Manager, and again rebranded to Ivanti Neurons for ITSM as part of another practice, the Shift-Left Methodology.
SDLC History
Iterative 1950s
Waterfall 1970
Spiral 1986
Agile 2001
Lean 2003
DevOps 2008
ITSM/ITAM/ESM Blog 