This example base might get you going in the right direction. I used a join table to join instances of an Asset being in possession of a Technician, a one-to-many relationship for Check records against that join table, and then conditional rollups to pull results and date of the most recent check into the Assets table.
Copy this base into your workspace and dive in to see how it’s structured. There may be modifications you should make so that it better fits your workflow, but like I said, I think it may at least push you in the right direction.
This is great, thanks for your help! I’ll have a play around. Can you advise on how each technician will interact with this? I don’t want to get too far down the rabbit hole without knowing what I can do!? For example Is it possible to create a form for each technician? They see each item and then mark it as checked? I don’t really want Tom to see Rich’s assets and checks.