Mary Poppendieck, Henrik Kniberg and a bunch of other people are on a Lean Tour in Japan that might turn out to be historical.  According to this blog post, a Toyota software development manager has spoken openly for the first time on how they develop software, and guess what? Yep, it’s waterfall. We’re waiting for more details on the Lean Development list regarding how they manage to pull this off and what they think of the Agile community, but I think we’re going to learn a lot here.

Update 2/May: this is what Mary says about what Toyota is doing and thinking

The person we heard from at Toyota – Ishii-san – deals with embedded software in production automobiles.  I understand that for a prototype part, software can take a matter of days.  In production parts, the cycle was 3 months.  When you are dealing with embedded software in production hardware, a 3 month waterfall is really fast.  And note that at Toyota, people really do talk about “bad news first”, so what we heard about is what they consider a problem, as opposed to what is going well.

To answer your question about agile, Ishii-san said they are studying agile, but their architecture is not particularly supportive of it.  His real motivation, as I heard his comments, is that improvement is necessary because of the late detection of defects.  I imagine that they will focus on early removal of defects, and adopt whatever processes prove (after PDCA cycles) to be more proficient at doing this.

Toyota people will not just do agile because someone says it is good.  They will look at their objectives and adopt whatever process gives them more of what they consider good.  And Toyota is  VERY good at doing this – I would not want to be competing against them!