ISO standard for central workshop

I am seeking a freelancer to help me implement an ISO standard for our central workshop. The purpose of this implementation is to improve efficiency and effectiveness. I am open to suggestions for the appropriate ISO standard, as I need guidance in this area. The ideal freelancer for this job should have experience in ISO standards and be able to provide expert guidance in choosing the appropriate standard. The implementation should be completed as soon as possible.

I need ISO for three section :

_ overhauling section ( finishing )
- lathe machine section ( machining )
- welding section ( iron work )

all ISO i cab implement here