Engineering Design Tolerance Analysis - Parts & Assemblies
Part & assembly tolerance analysis, when it just all stacks up 
Tolerances are vital part of the product design and the manufacturing methods selected. There's nothing worse than designing a beatiful product that just just can't be assembled becasue of a tolerances stack that either hasn't been accounted/designed for, or the incorrect manufacturing methods/materials have been selected. Every physical dimension will float wihint a range, and careful design of both the part and assembly plus the selected manufacturing method is required to stop tolerances becoming a problem. It usually equates that the tighter the tolerances of manufacture, the more cost is associated with production, until you're into precision engineering!