New manufacturing methods involving direct fabrication processes seem ideal for mass customization or “just-in-time” production. The use of tool-less means of production ensures reduced lead-time and lower cost. Besides, they provide flexibility in design and fabrication, which are essential for small lot sizes. However, part quality and production reliability are challenges that must be met. When adapted to the micro-factory paradigm, direct manufacturing can be made portable and capable of remote manufacturing. The benefits of miniaturization are savings in materials and energy consumption, but the increased surface area to volume ratio has implications for material behavior, especially mechanical strength. The newest incarnation of direct manufacturing is direct digital manufacturing or DDM, which involves localized deposition of material or energy and the creation of heterogeneous objects with digital means of control. DDM seeks spatial control of macrostructure, composition, texture and properties with the possibility of producing materials with unusual behavior, functionally gradient structures and integrated component devices. For DDM, multi-material design, precision in deposition, shaping and removal and understanding of heterogeneous material behavior are challenges.