What guideline do you recommend to use to comply with ISO 13485 regarding validation and computerized system validation. We will not need to comply with FDA guidelines. Please share any recommendation.
This basically depends on the type of the medical device that you have and regulations that you need/want to be in compliance with.
In general, in ISO 9001:2015 validation is defined as "confirmation, through the provision of objective evidence, that the requirements for a specific intended use or application have been fulfilled". As for medical devices, validation involves an "assessment by objective means of whether the specified users are enabled to achieve the specified goals (intended purpose) within the specified context of use".
Computer System Validation (CSV) is a documented process of assuring that a computerized system does exactly what it is designed to do. Requirements for validation of computer systems can be found in:
FDA 21 CFR part 820.70
FDA 21 CFR part 11.10
FDA 21 CFR part 11
FDA Guidance Document regarding Software Validation
ISO 13485, in chapters 4.1.6, 188.8.131.52 and 8.2.3
Good manufacturing practice directives
Guidance to achieve compliant computerized systems (GAMP 5), e.g. regarding the "risk-based approach of testing GxP systems"
For more information on validation, please see following articles: