DFM
DFM is Design for Manufacturability
Design for Manufacturability includes a set of techniques to modify the design of integrated circuits (IC) in order to make them more manufacturable, i.e., to improve their functional yield, parametric yield, or their reliability.
The most important Yield Loss Models (YLMs) for VLSI ICs can be classified into several categories based on their nature.
Functional yield loss is still the dominant factor and is caused by mechanisms such as misprocessing (e.g., equipment-related problems), systematic effects such as printability or planarization problems, and purely random defects.
High-performance products may exhibit parametric design marginalities caused by either process fluctuations or environmental factors (such as supply voltage or temperature).
The test-related yield losses, which are caused by incorrect testing, can also play a significant role.
http://en.wikipedia.org/wiki/Design_for_manufacturability_(IC)