how to remove brand name text (next to the logo) on obiee 11g home dashboards?

You can Customise OBI welcome page by overriding XML messages. Please follow the below steps to change the Brand Name:-

a. Create a directory named customMessages under <ORACLE_INSTANCE>\bifoundation\OracleBIPresentationServicesComponent\coreapplication_obips1\msgdb\l_en\
Note:- Please create l_en directory if this does not exist.
b. Create an xml file under customMessages directory.
c. Add the below contents inthis xml file and add any customised text you require between TEXT tag:-
--------------------------------------------------------------- <?xml version="1.0" encoding="utf-8"?>
<WebMessageTables xmlns:sawr="com.siebel.analytics.web/response/v1" xmlns:sawm="com.siebel.analytics.web/message/v1" sawm:systemMessages="false">
<WebMessageTable system="Custom Messages">
<WebMessage name="kmsgHeaderBIBrandName">
<TEXT>Customised Text</TEXT>
</WebMessage>
</WebMessageTable>
</WebMessageTables>
---------------------------------------------------------------

Restart Presentation services for the changes to take effect.

Method 2:

Removing BrandName text (next to oracle logo)  on obiee11g home page

D:\OBIEE_HOME\Oracle_BI1\bifoundation\web\msgdb\l_en\messages\productmessages.xml

For more:

for more refer
Customizing Oracle Business Intelligence Enterprise Edition 11g An Oracle White Paper
http://www.oracle.com/technetwork/middleware/bi/customizing-oracle-biee-11g-176387.pdf


Regards,

Deva