The client calls: "We have an injection-moulding line from 2014. The customer (Tier 1 automotive) wants to double volumes. Do we build new or refit the old one?" This is a decision made in millions of euros and the firm carries the consequences 7–12 years. And it's a decision where "it depends on the situation," while true, is absolutely unusable as an answer.
This article is the decision framework we've applied to ~30 projects in the €0.8–8M CAPEX range over the last 5 years. Five criteria, five concrete numbers — the output is indicative but in 80% of cases gives the client the right answer by the first workshop.
What's hidden behind "refit or greenfield?"
First: what does this actually mean?
**Refit (retool, modernisation)** — existing line, existing layout, existing buildings + infrastructure. Replace part: key machines (extruder, press, robot), automation (PLC + SCADA + safety), some auxiliary systems. Don't change: building, main media (electrical 1MV / 6kV transformer, water, gas), in 80% of cases not even the layout.
**Pretooling (mid-life upgrade)** — bigger than refit, smaller than greenfield. A significant share of equipment changes (50–70%), but the layout + building + main media stay. Often part of ramp-up to higher volumes.
**Greenfield** — a new line on a new plot or in a new hall. Everything from foundations: building, media, equipment, automation, IT/OT.
**Brownfield** — a new line in an existing hall (after demolition of the old one). Hybrid — uses existing buildings + some media (typically MV grid connection), the rest new.
Clients use these terms interchangeably. The first workshop call: define clearly what we're talking about.
Five criteria — decision tree
Criterion 1 — Installed-base value (what the existing line is actually worth)
Not book value (where the asset has 30% remaining amortisation but is technically worthless). **The actually usable value** in the new arrangement.
Three layers evaluated separately:
**A) Building structures:** hall, heating, layout, access. Value: if the hall is 15+ years old and building standards were 2008, a reassessment for the current code is needed (fire protection, evacuation, OHS planning). Often: 70–90% of value.
**B) Main media:** electrical (transformer, main switchboards), air (compressors, distribution), water (cooling tower, deionised water plant), gas (natural gas distribution), waste (waste water treatment). Value: if < 12 years, sized for the new volumes, 80–95% usable. If over-committed (needs upgrade for 2× volumes), either upgrade or refit isn't enough.
**C) Equipment (machines):** press, extruder, robot, conveyor. Value: drops rapidly with age + technological obsolescence. A 5-year Engel injection-moulding press has 60–70% of its original value. A 10-year-old has 30–40%. A 15+ year-old is "either working or for scrap."
**Rule:** if A + B sum ≥ 50% of total project CAPEX, **refit/pretooling is mathematically more favourable**. Below 30%, greenfield.
Criterion 2 — Downtime cost during refit
This is the line item that most often kills the refit business case. Refit means production loss — 2–12 weeks depending on scope. Greenfield within existing operations means zero loss (parallel build, switchover after commissioning).
**Calculation:** ``` Downtime_cost = (lost annual production) × (margin per product) × (months of refit / 12) ```
A concrete example — injection moulding for automotive interior trim: - Annual production: 4.2M units - Margin per unit: €1.80 - Refit length: 10 weeks = 2.5 months - Downtime cost: 4.2M × €1.80 × (2.5/12) = €1.575M
This is an **opportunity cost** that's added to the refit CAPEX. Greenfield with parallel ramp-up doesn't have this cost (but has higher CAPEX). Compare:
- Refit: €1.8M CAPEX + €1.575M downtime = €3.375M total
- Greenfield: €3.2M CAPEX + €0M downtime = €3.2M total
Here greenfield wins. **This is where the client most often goes wrong** — they compare CAPEX vs CAPEX and ignore opportunity cost.
**Exceptions:** - The client has two redundant plants / lines → the downtime of one can be shifted to the other → opportunity cost drops to 0–30% - Refit is done during a shut-down period (summer break, Christmas) → real opportunity cost drops to 20–40% - Customer accepts inventory buy-ahead → 4–8 weeks of production is pushed to stock before refit → opportunity cost drops to 40–60%
Criterion 3 — Regulatory upgrades triggered by the refit
For refits in the EU: if a modification of equipment exceeds the **substantial change threshold**, a **new CE marking** under Machinery Directive 2006/42/EC (or the new Machinery Regulation EU 2023/1230, effective 2027-01) is required.
Substantial change criteria (EU Blue Guide 2022): - Adding a new function or mode - Change of risk profile (new mechanical / electrical / chemical hazard) - Change of performance characteristics by > 20% (speed, force, temperature) - Substantial replacement of equipment (> 30% of components)
If the refit crosses the threshold, you need: - New Risk Assessment (EN ISO 12100) - New Safety Validation under EN ISO 13849-1 (PL category) or IEC 62061 (SIL) - New EC Declaration of Conformity - New technical documentation (technical file) - Re-validation training for operators
**Real cost of recertification:** €40–120k per machine, €15–35k for testing and documentation, €8–20k for training. For a whole line with 4–8 machines: €200–600k.
This is **always underestimated** in the initial refit budget. For greenfield this is already counted in the base CAPEX.
Criterion 4 — Physical footprint changes
A refit works if the new line **fits into the original footprint**. As soon as internal walls have to move, media have to reroute, utilities have to relocate, the refit price climbs exponentially.
**Triggers that destroy the refit business case:** - Capacity uplift > 50% → need for another machine → need for more footprint - Adding a new process (e.g. surface coating to a moulding line) → another environment, more media - Compliance upgrade (e.g. cleanroom requirement, ATEX zone reclassification) → rebuild a building element
**Rule:** if the refit needs construction work over €150k (new floor layers, internal walls, ventilation, fire suppression), greenfield is probably worthwhile. Construction work in an existing hall with running production costs 2–3× more than in a greenfield environment (extra protection, working hours outside production, multiple mobilisations).
Criterion 5 — Workforce reskilling cost
This aspect is always underestimated. A refit with a new PLC, new HMI, new robotic cell means retraining the existing team. Greenfield usually offers the option of hiring new people with the right skill set from the start.
**Real reskilling cost per technician:** - Operator reskill (HMI faceplate, basic recipe management): €1,500–3,000 + 80 h productivity loss - Maintenance reskill (PLC troubleshooting, safety system, motion control): €4,000–12,000 + 160 h productivity loss - Process engineer reskill (recipe optimisation, statistical process control, MES integration): €8,000–25,000 + 240 h productivity loss
For a plant with 12 operators + 5 technicians + 2 engineers: total reskill cost €150–280k. Plus 6–12 months until the reskilled team reaches pre-refit productivity.
Greenfield: doesn't need to reskill the existing team (it can stay on the existing line), the new team is hired with the requested skill set. Cost: hire + onboard 12 new people ~€80–120k + 3–4 months of ramp-up.
In some cases (existing team has high loyalty, low turnover, unique process knowledge) reskilling is an INVESTMENT, not a cost. In others (high turnover, burned-out team, unwillingness to change) reskilling is practically infeasible and the refit fails for operational reasons.
A real example — an injection moulding refit that won
Client: interior trim supplier for Volkswagen SK. Line from 2014, two Engel duo presses 500T + 800T, manual loading, OEE 71%. The customer wants to double volumes in 2027 — capacity uplift 60%.
- **Refit:** robot cell loading, Cognex visual inspection, Engel press refurbish, new Siemens S7-1500 + WinCC. CAPEX €1.8M, downtime 8 weeks split 4+4 (one line ran while the other was being refitted).
- **Greenfield:** two new Engel e-motion lines in a parallel hall. CAPEX €3.2M, downtime 0.
Applying the 5 criteria:
1. Installed-base value: hall 11 years old, MV transformer over-sized to 2.5× current load, equipment valuation €380k. Reusable €1.78M = 56% of refit CAPEX. **Refit favoured.** 2. Downtime cost: 0.95M units × €1.80 margin × (4/12) = **€570k added to refit.** 3. Regulatory: refit crosses the substantial change threshold → recertification €120k. 4. Footprint: new cells fit into the existing dimensions with margin. Construction work < €40k. 5. Reskilling: 18 operators + 4 technicians × €5,200 average = €94k + 6 months ramp-up.
**Final:** Refit €1.8M + €570k + €120k + €94k = **€2.584M.** Greenfield €3.2M + €120k hire/onboard = **€3.32M.** Refit won by €736k.
The real driver: the line fitted into the original footprint, infrastructure was over-sized, the team was strong and willing to reskill. Without any of these three factors the arithmetic would have flipped. Post-implementation (2026-Q1): the line is running, OEE 84% after 4 months of ramp-up.
When refit loses
Five situations where a refit business case fails:
1. **Hall / infrastructure is end-of-life** (25+ year structure, undersized electricals) — refit becomes "upgrade halfway, not enough." 2. **Compliance landscape has shifted** (Machinery Regulation 2027, AI Act 2026-08) — on refit it all triggers; on greenfield the process is upfront-by-design. 3. **Workforce isn't willing to reskill** — high average age, low engagement, history of failed change. Refit drags on and doesn't reach planned OEE. 4. **Customer demands a fundamentally different product** — different materials, different process. Existing machines can't adapt. 5. **Volume uplift > 100%** — refit can add 30–60% capacity through OEE + de-bottlenecking. Above 100% another line is needed.
A practical playbook — first workshop
About 2 weeks of work, €8–15k of consulting: (1) inventory of the existing line + valuation, (2) customer demand analysis, (3) workshop on the 5 criteria with quantification, (4) preliminary CAPEX estimate for both variants, (5) site survey + media audit for the refit variant, (6) detailed CAPEX + opportunity cost calculation, (7) final decision workshop with management. Output: a defendable decision with 80%+ accuracy against final CAPEX.
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*We run refit / greenfield decision workshops for production sites in SR/CZ/AT. The first consultation (90 min) walks through the 5 criteria on your specific project and gives you indicative CAPEX ranges for both variants before you commit to one or the other.*