class FirstViewPart extends ViewPart
{	
	private SecondViewPart getSecondView()
	{
		return getSite().getPage().findView(SecondViewPart.ID);		
	}
}

class SecondViewPart extends ViewPart
{
	/* view id as declared in plugin.xml */
	public static final String ID = "com.xyz.SecondViewPart";
}

class FirstViewPart ..
{
	public void init(IViewSite site) throws PartInitException
	{
		super.init(site);
		
		/* open second view */
		getSite().getPage().showView(SecondViewPart.ID, IWorkbenchPage.VIEW_VISIBLE/*VIEW_ACTIVATE*/);
	}
}