Hi Srinivas,
it is been a while since you asked, probably you have already found out yourself.
When you go into the Administration client, and go to 'Model' in the navigation pane, there is an item 'Context defaults' on the right side. Here you can set the defaults for the process flows.
It works fine when you set the default, eg. for category and time, in all models to the same dimension member, but it shows some inconsistent behaviour across the models, when you use different settings for each. This is for 10.0 with SP11.
Best regards,
Melanie