Hello Sir,
Go to t-code SWELS. Turn on the event trace. Come out of this t-code once you turn on the event trace. Now enter t-code MM01. Create the material that you want to create, SAVE the material, and come out of it.
Now go to SWELS again and Turn OFF the event trace and come out. Now enter t-code SWEL. Execute this report. You will get the business object and event that was triggered on saving a material in MM01. Then enter t-code SWO1 and analyse the business object that was triggered.
Now once you find the Business object and its event, you go to T-code SWDD. Create a new workflow and in the header of this newly created workflow, you enter the name of the business object and its event. Bind the values against it and activate the workflow.
Now each time a new material is created, your workflow will be triggered. Write methods for this and execute your logic. 
Regards,
Dnyanesh.