Writing code is not the same as fitting nuts and bolts onto car parts. It is not a mechanical skill. It does not involve repetitive actions. Building great software requires creativity. Yet, we are so keen to pursue processes influenced by manufacturing paradigms. The lean principles outlined in Mary and Tom Poppendieck's book Lean Software Development, have been widely interpreted and applied without context to software development. Even the Kanban method (which is essentially a way of managing the supply of components in Japanese manufacturing based on pull or capacity to work) can rarely be applied to the context of software development without sufficiently modifying the paradigms to suit the nature of software development itself.
Manufacturing deals with repetitive tasks, equal-sized chunks of work and supply and demand that can be predicted/tweaked based on trends and optimizing process scheduling, assembly line structures...