An interesting topic in the BPM group; end-2-end process improvement is over rated compared to optimization.
Sustainability of an enterprise requires ongoing continuous improvements. The enterprise must be engaged in making continuous simple common sense improvements and refinements to critical end-2-end business processes. End-2-end process improvement provides worth to the process steps along the way that may use and/or produce intermediate goods, services and information to reach the primary end.
Optimization will adjust processes to maximize efficiency and/or minimize cost within some specified set of boundaries, creating risk that the value stream will be compromised. Optimization is not without its merit. One would have to ask how will optimizing a process change the shape the enterprise as a whole and is there alignment with the overarching enterprise strategy?
End-2-end process improvement in my professional opinion is not over rated. Constantly improving end-2-end processes supports the strategy of the enterprise for constant improvement and sustainability.