I don't think this is really an analogy. This chain occurs with both in both physical manufacturing and software. In both, developers/design engineers design

I don't think this is really an analogy. This chain occurs with both in both physical manufacturing and software. In both, developers/design engineers design the product, leads make sure that everything stays within budget and time, and product managers get requirements through sales or marketing staff. There really isn't a difference with either process at all, and for software that's sold on physical copies, it's is the exact same process. The major difference between releasing software on the internet and making a physical product is the end of the entire process, where the product is built and sent to the customer. With a physical product, it has to be built, stored until sold, then shipped out. Also, unless your developers are so misanthropic that putting them in front of a client might just cause wars to break out, most of this chain can be circumvented by involving all parts of the chain in requirements gathering. The key part of the beer game is that none of the parties can talk to any party that's more than one link away from them. Finally, and this is myself being a nitpicky bastard, but the operations manager will almost never have direct contact with a client. They will be the ones that work with the developers, the leads, product managers, and suppliers to make sure that the product can actually be made with the given budget, and that every step of the production chain is working correctly. They will also work with marketing and sales to make sure that the projected demand will be met, and that the product actually gets out to the clients. A better position would be sales people, because they are generally the only point of contact users have with the manufacturer.