A case study is described in which enterprise resource planning (ERP) system validation is done for Ross Systems iRenaissance software by Cambrex. Cambrex developed and validated its ERP software and customized enhancements to comply with present U.S. and European regulatory guidances. The project included the development of one global validation strategy and methodology. All support acts were deployed at all GMP facilities. Basic to the validation program was adherence to Cambrex global compliance policy document called Perspective of 21 CFR Part 11--Electronic Records/Electronic Signatures. Each facility developed a plan to control its validation process and to assure compliance with applicable site-specific cGMP regulations. Plans included staged activities for examination and documentation of business processes, quality assurance programs of the system and software suppliers, cGMP criticality assessments, and validation lifecycle and support procedures. Phases described are program planning, business process model development, validation preparation and plan development, initial site plan execution, and repeat validations at successive sites. A sample listing of validation documents is included. The ERP implementation and validation was successful because all involved in the project were educated in the philosophy of and methodology for validation that had been developed. Software categories and validation approaches highlighted include operating systems (OSs), firmware, standard software packages, configurable software packages, and custom software packages.