From the day i got into the Core banking Space , i have always heard of two modes of core banking deployment model, go step by step or go big bang. When the deployment is step by step, there is an option to go either by module wise or go by geography wise, but in the later there exist only one way go all out. Is there a way out of these standard models ? 

Just to ponder over, we shall look at the pros and cons of the widely used above two deployment models. Deployment life cycle  is much longer consuming between 30-40 Months on average. Lets take a case of a regulatory requirement taken for tailoring the core system, by the time it goes for the production after 2 years, the requirements are becoming void. Do we raise flag to the deployment model or to the highly volatile changing requirements ? Neither would be an answer would most of us agree, Its the systemic expectation would have to be pin pointed. Does it demands another specific link in the IT Value Chain of a bank. Its time for looking at IT-Strategy with specialised system for specific set of needs creating a well rounded IT-Ecosystem. An IT Ecosystem could generally be any combination of a Enterprise Subsystems cutting across the complete value chain of the banking operations. for E.g. From Customer origination, Product Origination, Selection, Processing , Servicing, handling Channels, handling payments, handling regulations, handling managment Reporting, handling analytics, handling treasury, risk and create intelligence for further customer originaiton.