The thesis work aims at providing analysis and design tools to tackle complex thruster placement and orientation problems for spacecraft with electric propulsion systems. The methods developed have been tested and applied within the first design phases of the NGGM mission by ESA as an instrument to identify feasible layout configurations capable of providing proper redundancy in case of a random single thruster failure and comply with the input control laws, in an aim to reduce fuel consumption and therefore decrease the overall propellant weight.