About
Paul McDonnell — Manufacturing Engineer
Paul is the engineer behind ReThink Manufacturing. Decades on the production line, working hands-on with textile machinery, and a practice of root-cause investigation before any change is made.
On the line
My background is on the manufacturing floor rather than in a design office. For decades I have worked hands-on with the machinery that makes textile products — quilting, embroidery, web forming, laminating, downstream finishing. I have set machines, changed machines, diagnosed machines, and learned which physical details matter and which look important but do not. Most of what I know about manufacturing engineering came from standing next to people who operate the equipment every day, watching fault patterns develop, and being told no when an easy explanation turned out to be the wrong one.
From firefighting to prevention
For most of my career the work was reactive — clear the fault, keep the line moving, deal with the next one tomorrow. That approach keeps production going, but it leaves the underlying causes in place, so the same faults come back in different forms. The shift to root-cause and preventive work was not a change in tools. It was a change in discipline: investigate before changing anything, prefer evidence over assumptions, and treat every recurring fault as a symptom of something the system has not yet told you. The people doing the work have always known more than the machine, the ticket, or the planner has recorded — the job is to listen to them and then to verify what the process is actually doing, not what we assume it is doing.
Observe before changing
Every engagement begins with observation. I watch the complete production process under normal operating conditions — not a setup, not a demonstration, not a single shift, but the full cycle across multiple shifts and through normal variation. The first suspected cause is almost never the real cause. Suspected causes come from whoever was nearest the fault when it happened, and they are shaped by what is visible from that viewpoint. The real cause is usually further upstream or further downstream, and it is rarely the component that has already been replaced. Watching the whole process first often reveals what no interview and no static inspection can.
Fix, do not replace
Wherever possible the solution is a simple engineering modification — a re-shim, a re-alignment, a guide adjustment, a timing correction — using what is already on the machine. No replacement parts are required in most of the work I do. Replacement is the default the supply chain offers, but replacement addresses a consequence; a modification that resolves the underlying geometry or sequencing addresses the cause. The work is measured by outcomes — production time recovered, faults that have not returned, capability left with the team — rather than by days on site. Every engagement is documented: what was suspected, what was observed, what was actually wrong, what was changed, and what to watch for if it returns.
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