Hi Praveen,

Initializing a work object from File Listener you meant Creating a Work object ?

Creating a work object is done by standard Pega activities like svcAddWorkObject. You can use such activities in your service activities referenced in various Service Methods(like SOAP, REST, Email, File, HTTP, Java etc) to create a Work objects automatically. 

-Harish

Hi

You can automatically create workobject in one of the following way : 

1. Via email listener : Outbound emails are processed and can create workobject . Refer https://pdn.pega.com/how-inbound-email-processed

2. Via triggering an activity inside another flow :Refer :  https://pdn.pega.com/how-automatically-create-new-work-object-and-transfer-it-subflow

3. If you have case designer then you can define the dependency between parent and child in such a way that upon creation of parent case, child case gets initiated automatically. Refer : https://pdn.pega.com/sites/pdn.pega.com/files/help_v719/procomhelpmain.htm#tools/casedesigner/casewideproperties/instantiation/tsk_configureautomaticinstantiation.htm

Hope this helps.