Agree that a 5Ys or PPS approach could be good on these, I prefer the latter or at least using a fishbone. Here's an explanation on how to do one: What is a Fishbone Diagram? Ishikawa Cause & Effect Diagram | ASQ
You really need people in your facility to truly understand the why of what happened but I've suggested a few questions which could point to potential immediate or root causes to each:
-The floor in the preparation area around the drain is found damaged; that could be difficult to clean
Measurement:
Machines: Are any of your machines or equipment causing the damage? E.g. wheels?
People: Why has this damage not been reported? Do people understand damage near drains is a high risk? Is there a knowledge gap?
Environment: Is the area always wet so difficult to make repairs "stick"? Is the lighting good enough to see the damage?
Materials: Is the flooring material fit for purpose with the traffic you have?
Process: How do you inspect fabrication in your factory? How are repairs in high risk areas prioritised? How do you budget for fabrication maintenance and make sure it's being spent? Do you have a near miss process which should have picked up an unsafe condition (as this is likely to be a H&S issue too?)
-Catch pan used to prevent oil leaks in the line 2 in the preparation area was observed with holes
Measurement:
Machines: Is the catch pan needed? Can the leak be repaired and prevented instead?
People: Why has this damage not been reported? Do hygiene staff who may see it when cleaning or operations staff know their responsibilities to report this?
Environment:
Materials: Is the catch pan material it's made from fit for purpose?
Process: How is the catch pan cleaned? Is it removed so easy to inspect at that point? Is that in the process?
-Equipment knives of the onion's peeler and removable knives in the processing area were noted rusty spots. As well as lubricant excess observed in the knives chain in the onion peeler.
Measurement: Is there guidance on the amount of lubricant to add?
Machines:
People: Why has this over lubrication and rust not been reported, do engineers and operations staff know their responsibilities to report this?
Environment: Is the area constantly wet or has use of chlorinated caustics (which can stain SS).
Materials: Are the knives and lubricants fit for purpose and designed for use? SS may stain with chlorinated chemicals but shouldn't rust.
Process: What pre use inspections do you have? Are they asking questions like these to be reported?