(No Agent) Error

Hi Experts,

I have done a BPM in my system. There is no error in the design and configration. A work Flow was created for My BPM . When i try to execute the BPM it is not successful . When i go and check the work flow , the first step itself has a error saying (No Agent) Error . What is a agent ?

Do i have to assign it for every work flow ?

How do i solve this issue ?

Regards,

Vignesh