Siebel Administration >  What will be the default activity status when a new activity is created

This is defined in Siebel Tools.

Activities are defined by Business Component 'Action'

Search for this Business Component, expand the Business Component sub sections.

In the sub section 'Fields', search for field 'Status'.

In the tab - 'Predefault Value', look for the expression.

This defines the initial status of an activity. e.g.

Expr: "IIF (ParentBCName() = 'Opportunity', LookupValue('EVENT_STATUS', 

'Scheduled'), LookupValue('EVENT_STATUS', 'Planned'))"

This means that if the business component name is Opportunity 

the status is scheduled, otherwise it is planned.

Activity Status is Column - EVT_STAT_CD of table s_act_evt.