On migration to Perpetual Enterprise System

Overview This document describes a pragmatic approach on how to migrate enterprise computer systems to new systems that could evolve forever, address the whole organisations and that are integrated. Governance aspects are as important, if not more, than purely technical IT aspects: human resources, supply chains, call for tenders, and similar. Migration implies not starting from a green field. Style of this document {Principle} Lie if it helps and restate the obvious. Enterprise IT architecture is a complex field. Efforts have been made to make this document accessible to the widest possible public, including non-IT people. To make concepts more accessible, they might be introduced informally without being technically strict (lie) and sprinkled with bits of tutorials (restate). For the gory details follow the references. It could be anything: from one integrated system to many disconnected systems, from properly developed systems to spreadsheets, from internal developed code to external libraries, etc. The first priority is to ensure the functioning of the current system, imperfect as it might be. Avoid the syndrome of not maintaining the current system because it is a waste of money. It is an error to channel most of the IT resources into the new wonderful system on the way. The first step is to prepare emergency manuals for the current system. The guiding scenario for preparing these manuals is that present IT staff operating/maintaining the current system disappear from one day to the next; unpolished manuals would do. New IT replacement staff without any previous knowledge should have a sporting chance of operating/maintaining the current system with the help of emergency manuals which must be printed and stored in a place easy to find.