Now, I am not an expert on manufacturing, but I have seen some. Software development is not manufacturing. I don't think that it's even very much like manufacturing. Manufacturing is about achieving uniformity across huge numbers of multiples and making some trade-off between the highest and the most economic rate of production of those multiples.
Software development is about making one.
I believe that software development is more like product development than manufacturing.
I'm not an expert in product development either, but I work for a company that, amongst other things, does develop products. Product development is very different from manufacturing (which we don't do), although the two are very closely related. A big part of product development is to arrive at a design that can be effectively manufactured.
Unfortunately a lot of our clients don't want you to know that we designed their products, so I can't brag too much. Which is a shame as a lot of them are waaaay cool. However, this flier[pdf] is public and describes one episode of product development. The flier mentions PEP, our process for developing products. As a deliberate policy we try to keep the processes that we use to develop products and the processes we use to execute software development projects as closely aligned as possible.
Both are iterative. Both involve exploration. Both are adapted to circumstances while maintaining certain principles (such as actively managing risk). Both have delivered a very high success rate over many, many engagements. So I feel on fairly firm ground in claiming this similarity between software development and product development.
As Steve Freeman points out, by a strict Lean interpretation of the manufacturing school product development looks wasteful. And it is. And that's OK because it isn't manufacturing. The economics and the goals are different.
Its worth noting that the highly-publicised Lean successes seem to be concerned largely with operational activities: never-ending, on-going care and feeding of an existing system. To the extent that your activities are like that, a more Lean approach is likely to work well for you, I think. I've yet to hear of a success story of strict Lean (no iterations, no retrospectives, all the rest of it) run in a project setting to produce a new product.
I don't say it can't be done, but I've not heard of it. If you have, I'd love to.