IBM & Six Sigma doesn't tally.
One thing should be clarified upfront..
IBM has their own methodology; IBM Global Services Methodology (v3.3 currently), which is followed by default in every engagement and all internal activities. No one has a choice in this (ie, whether an engagement can use IGS / 6 Sigma / etc)
Therefore Six Sigma for a scale of this magnitude would never be signed off by the old greyheads. Bearing in mind, LEAN can only be part of a full DMAIC cycle eliminates any choice to cut & paste LEAN into IGS process.
Unless they wanted to term elimination activities as "Project LEAN" !!!