Do I have to validate something silly like Microsoft Word as a software tool for my QMS?

It is unlikely that you will need to validate Microsoft Word, because most people don't use automation in their Word documents. However, Microsoft Excel is frequently automated for things like inspection forms. Therefore, you would need to validate some spreadsheets.

The applicable clause is ISO 13485:2016, Clause 4.1.6. In addition, there are two other related clauses:
1. ISO 13485:2016, Clause 7.5.6 for process validation (i.e., automated production equipment)
2. ISO 13485:2016, Clause 7.6 for calibration software (e.g., Gage Track)

The standard for validating quality system software is ISO/TIR 80002-2:2017. You can purchase the software at: https://array.aami.org/doi/10.2345/97.... Make sure you have AAMI membership to get a member's discount on standards. The standard is 103 pages and has examples in the back for how to validate various types of documents.

We also have a procedure and templates we sell as part of our turnkey quality system.
https://medicaldeviceacademy.com/stan...
The procedure is SYS-051, Software Tool Validation. You can purchase this at:
https://medicaldeviceacademy.com/soft...

When you are creating a quality plan for software tool validation, you should start by creating a list of all of your software. Then you need to define what quality-related function each software performs. Most software only has certain functions that are quality related. Then you use a risk-based approach to prioritize validation and to decide the extent of software validation you will perform. You can use our procedure and templates to help you, or you can use the guidance document (i.e., ISO/TIR 80002-2:2017) to help you create a validation protocol for each software tool. We recommend you create a generalized template for each software type that you can fill in the blanks for rather than creating a completely new protocol for each type.

We will have a training webinar later this year for SYS-051. If you would like to see it soon, then please comment on this video.