A Plant Manager's First 90 Days: What To Fix First

New plant manager, day one, and the first thing on your desk is a stack of capex requests from the previous regime. A new forehearth. A batch house automation upgrade. A second cullet crusher nobody's costed properly. Every one of them promises a step change. None of them will move the needle in your first ninety days, and if you sign off on the wrong one you'll spend the next two years explaining the payback that never showed up.

I've walked into six plants as an outside pair of eyes over the past decade, and I've run three as the guy actually holding the P&L. The pattern repeats. The furnace is rarely the problem. The mould shop is rarely the problem. The recoverable EBITDA is sitting in three or four unglamorous places that nobody has measured properly in years, and most of it costs nothing to fix except attention.

Start with cullet ratio, not the furnace

Cullet ratio is the single biggest energy lever a plant manager controls directly, and it's controllable from week one with zero capex. Each 10-percentage-point increase in cullet usage cuts furnace specific energy consumption by roughly 2.5-3% and lowers CO2 and NOx per tonne melted. If your plant is running at 35% cullet when the batch house could reasonably handle 50%, that gap is your first number. Not the exotic one. The boring one.

In Europe this lever is sharper than most plant managers give it credit for. EU glass packaging recycling reached roughly 76% in 2022 under FEVE reporting, with Belgium and Slovenia clearing 95%, which means a well-positioned European plant has cullet supply sitting on the table that a GCC plant simply doesn't. UAE and Saudi container glass operations compete on genuine cullet scarcity, since post-consumer collection infrastructure across the Gulf lags Europe by a wide margin, and that forces higher virgin batch ratios and higher furnace draw as a structural fact of the region, not a management failure. If you're a plant manager in the GCC, don't chase a European cullet target you can't hit. Chase batch-house redox control instead, because that's the lever you actually own.

Which brings me to the second thing I check before I've finished my first plant walk: redox. Fe2+/Fe3+ control in the batch house governs colour consistency, especially amber, and it's the most common root cause flagged on hot-end QC boards for seed and blister spikes. If your QC board has a recurring blister problem and everyone's blaming the furnace crown, ask the batch house for the redox trend line first. Nine times out of ten that's where it starts.

Job change time is where the fast money actually is

Standard job-change downtime on a mould or format changeover should sit under four hours. Best-in-class plants with pre-staged tooling and a standardised checklist run under two. I worked a five-line plant in 2014 where cross-shift job change variance on the exact same SKU ran anywhere from 90 minutes to just over five hours, depending entirely on which shift was on the floor and whether the mould shop tech had prepped ahead or was starting cold. Same product. Same moulds. Same line. Nearly four hours of daylight between the best crew and the worst.

That variance is not a training problem you solve with a memo. It's a systemisation problem. Industry OEE benchmarks put the average container glass plant at 65-75%, with top-quartile operations running 80-85% or better, and the gap between those two numbers is traced most often to changeover time and unplanned hot-end stops, not raw machine speed. A 1% efficiency improvement at hot-end scale is worth millions in EBITDA on a plant of any real size, and job change is the fastest, cheapest place to find it because the machine doesn't change. The behaviour around the machine does.

This is exactly what our Job Change Tool was built to fix, and it's worth being precise about what it is. It isn't a generic SMED for container glass template borrowed from an automotive line. It's a systemised, vendor-neutral method mapped to the 9-stage Job Change Lifecycle, from plan and prep through line-down, mould change, recipe load, ignition, first ware, stabilise and post-mortem, with a named owner at every stage so the 0600 handover isn't relying on someone's notebook. And that handover gap is real. On most lines I audit, the night-shift swabbing data doesn't make it into the morning handover in any usable form more than seven times out of ten. The information exists. It just doesn't travel.

The furnace gets the capex request. The changeover gets the shrug. Ninety days in, it's always the changeover that was costing you the millions.

Check gob weight and mould temperature before you touch anything structural

Two numbers I want on a whiteboard by week three, not week thirteen: gob weight CV and mould temperature band. Gob weight control on IS machines is normally held to ±0.3-0.5g, and a sustained 1g drift can add 0.5-1% to pack-to-melt yield loss across a job run. That's real tonnage walking out the back door as cullet you didn't plan for.

On NNPB (narrow-neck press-and-blow) lines, watch the blank mould temperature band too. Drift outside the 480-520°C target range pushes check-defect rates on the finish or neck above roughly 0.3% of inspected containers, and check defects are one of those failure modes that looks like a forming problem but is almost always a mould-shop maintenance and lubrication issue. Don't let anyone tell you it's a machine-speed problem until you've pulled the mould temp log.

None of this requires new equipment. It requires someone walking the floor with a checklist and comparing what the SOP says against what's actually happening on section four at 3am. I've seen plant managers commission a six-figure automation study before they've confirmed their own gob weight is in spec. Wrong order.

Where the regulatory and market picture actually changes your priorities

Region matters more than most 90-day plans admit. In the US, O-I's Fit to Win restructuring targeted somewhere in the order of $180-230 million in structural cost reduction through furnace curtailments and closures across 2023-2024, and Ardagh idled or closed lines including its Dunkirk, Indiana facility in the same window. If you're managing a North American plant right now, that's the competitive backdrop your board is reading, and California's AB 793 phasing in a 35% post-consumer recycled content floor from 2025 is a direct cullet-sourcing constraint if you're anywhere near the West Coast supply chain.

In Europe, EU ETS allowance prices have traded broadly in the €60-€80/tonne range through 2024-2025, a direct line-item hit to furnace fuel cost, and Fit for 55's 55% net GHG cut target by 2030 is tightening the free-allocation benchmarks under ETS Phase IV. CBAM's definitive regime started 1 January 2026 and doesn't cover glass yet, but it's flagged for scope extension, and a plant manager who treats that as a legal department's problem rather than a furnace-campaign planning input is going to get surprised. GCC glassmakers, by contrast, still benefit from government-regulated natural gas feedstock pricing well below European market-linked rates, which is a structural energy advantage worth remembering before you copy a European playbook wholesale into a Saudi or UAE plant. Saudi Arabia's Vision 2030 import-substitution push is also lifting domestic demand for locally produced glass packaging, which changes the growth conversation entirely from the margin-defence conversation a European plant manager is having.

What to leave alone in the first 90 days

Don't touch the furnace campaign unless you have a genuine safety or refractory failure signal. Campaign life typically runs 10-12 years between cold repairs, and scheduled hot repairs like checker replacement or bottom patching exist precisely so you don't have to make a panic decision in month two. Don't reorganise the shift structure either, not yet. A hot-end shift typically runs a supervisor, one IS operator per two to three sections, a dedicated job-change technician, and a batch house operator holding bath temperature to ±1-2°C and forehearth conditioning to ±1°C. If that structure is functioning, your job in the first 90 days is to measure it properly, not redesign it from a whiteboard on your second week.

And don't let an OEM-affiliated consultancy talk you into a capex programme framed around their own upgrade cycle before you've confirmed your existing IS machine, forehearth and batch plant can already hit target KPIs without spending a cent. That's the single biggest trap I see new plant managers walk into, because the equipment vendor's incentive and your incentive are not the same thing in that conversation.

Ninety days is enough time to know where your EBITDA actually is. It's not enough time to fix everything, and trying to is how plant managers burn political capital on the wrong fight. Start with a proper management audit, get the changeover and cullet numbers on the wall, and let the data tell you which capex request earns its place next year.

If you want a second pair of eyes on that priority list, Lean Glass runs a management audit built specifically for the first-90-days problem, run by an operator-led consultancy that's done this from the plant manager's chair, not from a sales deck.