OAGIS XSDs

We are using OAGIS standard in our project.
We try to create document type using the xsd ,but we get multiple schemas created.
Also we need to create xsd out of this generated document type in developer and pass it to our source system.
When we do this using createxsd service in pub folder,we get multiple xsds created?How can we have just one single valid xsd created out of document type?

Please help if anyone already worked on OAGIS standard

Any particular schema/xsd you have these issues?

We use xsds like ReceviePO,processMoveInventory,NotifyShipmentSchedule etc

What tool are you using? What is the Source document if you already have the schemas from OAGIS?

We use tools like xmlspy to create xsd out of the xml schema.
Also we tried using createXSD service within wmPub