The main purpose for this project, Flexible Weapon Systems, has been to use the results from different research project at the technical level within the weapon area at FOI to build up knowledge on higher systems levels as tactical and operational levels. Another purpose for the project has been to be the contact between the FOI and the Swedish Armed Forces and the procurement organisation, FMV, in the weapon area. The aim for the project has been to build up a capability at FOI for assessment and evaluation of weapons and weapon system at different levels as technical, tactical and operational levels. This capability is based on the knowledge in the weapon area together with methods for assessment and evaluation with the support of different simulation tools. This report presents the last results from the project regarding methods and tools for the support of assessment and evaluation of weapon systems.