From EPC Standard
Attributes are part of the EPC meta model. They are used to specify process elements and to alter them in a specific way to meet possible requirements of EPC extentions. 
- [*1] Jannaber, S., Karhof, A., Riehle, D. M., Thomas, O., & Delfmann, P.: "Invigorating Event-driven Process Chains – Towards an integrated meta model for EPC standardization", 1st International Workshop on Adequacy of Modelling Methods (AQEMO’2016), vol. 255, pp. 13-22, 2016.