This report describes the work carried out in the project Combined weapon systems assessment which is part of the Swedish Armed Forces research programme Weapons and protection. The project duration is three years starting 2020, and the results presented in this report constitute a summary of the work done during the first year of the project. The main goal of the project is to develop methods and tools in order to study, analyse and assess the explicit or implicit contribution of different weapon systems to combat effectiveness; applied to both existing operational and future weapon system concepts. The project has continued the development of a tool for simulating autocannons used in anti-air applications and implemented a simulation model for assessing combats effect of indirect fire. In addition, an overview of existing software used for scenario evaluation has been compiled together with the needs and requirements for future scenario tools. Within the field of weapon systems assessment studies have been carried out focusing on future indirect fire weapon systems, urban warfare and loitering munitions. A new method, evaluating combat effectiveness for armed warfare, has been developed and documented.