Agile and Trust
Change in requirement involves rework and it may imply discarding work already done. If IT believes that the change is due to carelessness or inefficiency of business then the result would be acrimonious.
Similarly, there are features which look simple from outside but are complex from inside. If business believes that IT has unnecessarily inflating the estimate than it would have same acrimonious result.
On the other hand if IT believes that the change is needed and could not be specified earlier and business trusts the estimate provided by IT then you improve the level of trust between IT and business.
When the work has been outsourced then this problem becomes even more prominent.
These situations and not new and traditional heavyweight methods were build assuming such problems exist.
Agile assumes that such problem can be overcome through trust.
But, how to move to a position of trust? Would trust develop if you implement agile? Or, would it be necessary to build the trust before attempting agile?