ISO 45001 - Resources needed to implement

My question is this: Our company has 350 employees, and 9 bldgs. How big a team do we need to prepare the site to understand the certification process and their important role in the implementation of the OHS, and then go through the certification process with a registrar?

Answer:
First, I want to point out that you should not be implementing both ISO 45001 and OHSAS 18001. OHSAS 18001 is an older standard that is being replaced with ISO 45001, and will be made obsolete in the next 3 years, so the newer ISO 45001:2018 standard is the one you should use.
As for how many people you need, this question can be trickier. This can depend on many things, most importantly the number of different processes in the company. For instance, the ISO 45001 standard asks that you assess the OH&S hazards for your processes, but if you use the same process in each of your 9 buildings you would not need to perform th is activity 9 times; only I time per process. What can be the best help is to us a gap analysis tool to see how much of the standard requirements you already have in place, then you can try to assess how much work is left and therefore how many people you need to do this work in the time needed. We have a free, online gap analysis that you can assess here: ISO 45001 Gap Analysis Tool, https://advisera.com/45001academy/iso-45001-gap-analysis-tool/
Another helpful tool to understand exactly what will need to be implemented is our downloadable whitepaper which explains the requirements in an easy to understand format. You can find this here: Clause-by-clause explanation of ISO 45001:2018, https://info.advisera.com/45001academy/free-download/clause-by-clause-explanation-of-iso-45001 You might also want to review our diagram for the implementation and certification process; Diagram of ISO 45001 Implementation Process, https://info.advisera.com/45001academy/free-download/diagram-of-iso-45001-implementation-process