The European Air Quality Directive (Directive on ambient air quality and cleaner air for Europe) identifies different uses for modelling: Assessment, planning, forecast and source apportionment (SA). This CEN/TS addresses source apportionment modelling and specifies performance tests to check whether given criteria for receptor oriented source apportionment (RM) are met. The scope of the tests set out in this CEN/TS is performance assessment of SA of particulate matter using RM in the context of the European Directives 2004/107/EC and 2008/50/EC (AQD) including the Commission Implementing Decision 2011/850/EU of 12 December 2011. The application of RM does not quantify the spatial origin of particulate matter hence this CEN/TS does not test spatial SA.This CEN/TS addresses RM users: participants and organisers of source apportionment intercomparison studies as well as practitioners of individual source apportionment studies. This CEN/TS is suitable for the evaluation of results of a specific SA modelling system with respect to intercomparison reference values (a-priori known or calculated on the basis of participants' values, see 3.12) in the following application areas:- Assessment of performance and uncertainties of a modelling system or modelling system set up using the indicators laid down in this CEN/TS.- Testing and comparing different source apportionment outputs in a specific situation (applying an evaluation dataset) using the indicators laid down in this CEN/TS.- QA/QC tests every time practitioners run a modelling system.It should be noted for clarity that the procedures and calculations presented in this CEN/TS cannot be used to check the performance of a specific SA modelling result without having any a-priori reference information about the contributions of sources/source categories.The principles of receptor oriented models are summarised in Annex A. An overview of uncertainty sources and recommendations about steps to follow in SA studies are provided in Annex B and Annex C.There are different methodologies than RM widely used to accomplish SA, e. g. source oriented models. These other methodologies cover aspects of SA which are required in the AQD and are not addressed by RM. Performance assessment of such methodologies is out of the scope of this CEN/TS.