Different agile methodologies are used in traditional desktop applications today. These agile methodologies often try to eliminate development risks in early design phases. Possible solution is to create a working model or a prototype of critical system parts. Then we can use this prototype in negotiation with customer and also to prove technological aspects of our solution. From this perspective functional languages are very attractive. They have excellent abstraction mechanism and they can be used as a tool producing a kind of executable design. In this paper we present our work on a domain specific functional language targeted to embedded systems - Embedded process functional language. Created language works on a high level of abstraction and it uses other technologies (even other functional languages) created for embedded systems development on lower levels. It can be used like a modeling or a prototyping language in early development phases.