The part works, but the design makes it expensive to manufacture
Manufacturing cost is often locked into the drawing before a shop quotes the job. Extra setups, unnecessarily tight tolerances, difficult tool access, welding, manual finishing and special components repeat on every unit.
What does a DFM cost review look for?
Part count, manufacturing route, setup count, tool access, tolerances, surface requirements, material form, welding, inspection burden, standard components and whether the design matches the equipment that will actually make it.
Why can a tolerance make a simple part expensive?
Tighter-than-needed tolerances can force different workholding, process control and inspection. The useful question is not “how tight can the shop hold it?” but “what tolerance does the function actually require?”
Is the cheapest individual part always the best design?
No. A cheaper component can increase assembly time, inspection, failure risk or sourcing difficulty. The target is lower cost of delivering the required function, not the lowest price of each line item.
Example: DC36 sheet-metal enclosure
In one enclosure project, geometry and bending changes reduced welding and manual finishing. Project records report up to 35% lower cost and up to 15% shorter cycle time for that specific design; those figures are not a general performance promise.