How do I send data to Appian, to start a process model from third party applicat

@philb : if the external system is not sending email then, other than writing a servlet plugin what all are options for solving this problem.

As Joel says, you can also publish a process model as a web service for the external system to call.

ok thanks.philb

Thank you all, I will try to implement this.

So basically I would need to send username and password mandatory, plus any process variable that is set as paramater in my process model.
This parameter can then be accessed using pv!processVariableName ?

How will I view this Process Model in Browser?

I suggest you set up a test process model and publish it, then call it with an external tool such as SoapUI to see what the call looks like.

Yes, I saw that. if I want to view this process model in the browser with the data that I sent to the web service of the model, how will I do that?

i.e, I want the process model to start once the data is sent to it through the web service call in a browser

The response of this process model, gives a long? Which is a process ID? or is it a task Id?

I think if its task id, then we are sorted, and I can use that taskId in embedded html to start the process.