How to Successfully Renovate a Controls System? - Lessons Learned from the Renovation of the CERN Injectors’ Controls Software

Renovation of the control system of the CERN LHC injectors was initiated in 2007 in the scope of the Injector Controls Architecture (InCA) project. One of its main objectives was to homogenize the controls software across CERN accelerators and reuse as much as possible the existing modern sub-systems, such as the settings management used for the LHC. The project team created a platform that would permit coexistence and intercommunication between old and new components via a dedicated gateway, allowing a progressive replacement of the former. Dealing with a heterogeneous environment, with many diverse and interconnected modules, implemented using different technologies and programming languages, the team had to introduce all the modifications in the smoothest possible way, without causing machine downtime. After a brief description of the system architecture, the paper discusses the technical and non-technical sides of the renovation process such as validation and deployment methodology, operational applications and configuration tools characteristics and finally users’ involvement and human aspects, outlining good decisions, pitfalls and lessons learned over the last five years.