BPO versus BTO? Not exactly

There are major differences between Business Process Outsourcing and Business Transformation Outsourcing so the best thing to do is define both and analyze the differences:

BPO - Business Process Outsourcing:
Business process outsourcing means examining the processes that compose the business and its functional units, and then working with focused service providers to both re-engineer and outsource these at the same time. BPO involves the full transfer of responsibility for functions such as transaction processing, policy servicing, claims management, HR, finance, and compliance to the outsourcing company. The outsourcing provider then administers these functions on their own systems to agreed service standards and at a guaranteed cost. Some of the BPO contracts call for performance-based payouts, tying vendor payments to business performance or overall cost savings.

BTO - Business Transformation Outsourcing:
Business transformation outsourcing (BTO) is a natural extension of the more tactical BPO model and involves the transfer of responsibility for all back-office functions, as well as a comprehensive business change management process to an external vendor. The objective is to maximize the long-term benefits of the BPO operations, resulting in a comprehensive business transformation (or overhaul). Transformation outsourcing is not a tactical issue but a forward-looking strategic tool for change. The logic: big gains in performance only come about through business transformation.