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TPM · OEE · ROI

What an OEE percentage point is actually worth

July 2026 · 6 min read

Every ROI calculator promises the same big number. Then the pilot lands and by month six the actual saving looks a third of what the calculator quoted.

The platform didn't fail. The calculator was quoting the median of what other vendors claim, not the median of what real plants achieve.

Vendor calculator
₹18 Cr
Year-1 savings on a ₹200 Cr plant. +8 pp OEE. 30% downtime cut. Payback in 4 months.
Median of vendor claims. Not year-1 outcomes.
What plants report
₹2 – 4 Cr
Year-1 range across 30-plus published TPM case studies. +4 to +7 pp OEE typical.
Steady state at 18–24 months often reaches 1.5–2× this.

A plant CFO can spot a 25× number from the specification sheet. The math has to survive their calculator, not just ours.

OEE, without the lecture

One number. Three multipliers. Downtime, speed, defects.

A
78%
Availability
×
P
82%
Performance
×
Q
97%
Quality
=
OEE
62%
Overall

World-class discrete manufacturing sits around 85%. Typical mid-market plants land in the 55–70% band. Six Big Losses feed into A, P, and Q; each of the 8 Pillars of TPM plugs into a different piece of the same number.

The framework is out of scope for this post. The TPM page maps each loss and each pillar to what EdgeBits does under it. Here we're just doing the money.

The quiet cheat, in two steps

1

Adding A, P, Q lifts as if they were independent

They aren't. Fixing Small Stops moves hours between the Availability and Performance buckets rather than adding to both. Sum them naively and you double-count at the margin — typically 12 to 18% overstatement.

2

Quoting the ceiling as if it were year one

The lifts vendors advertise are what plants can reach at 18–24 months with sustained focus. Year-1 numbers are typically 50–70% of that. Calculators quote steady state; buyers get charged for year one.

We did both of these in our own calculator initially. We took them out.

What we replaced them with

Conservative year-1 defaults. A 15% coupling discount on A and P. A 1.3× boost when the operator declares which loss is the Top Loss, because Focused Improvement teams reliably outperform generic lifts on their attacked bucket.

Every number cites a real 2025–2026 source. The full assumption table sits inline on the calculator page, next to the sliders — the plant CFO can read it while running your plant.

What it looks like on a ₹200 Cr plant

Top Loss: Unplanned Stops. Currently pays for a commercial historian. Manual reason-code capture on the shop floor.

Today
62%
A 78 · P 82 · Q 97
+6.5 pp
Year 1
68.7%
A 82 · P 85 · Q 98

The rupee value, after coupling and Top-Loss adjustments:

Revenue₹200 Cr
Uplift factor (0.687 / 0.620 − 1)10.8%
Contribution margin12%
Output uplift₹2.60 Cr
Reason-code FTE freed₹6 L
Historian licence eliminated₹15 L
Year-1 estimate₹2.80 Cr
1.4%
of revenue. Repeatable. Boring, in the best sense.

Steady state at 18–24 months is typically 1.5–2× this. Plants that install and don't act on alerts save close to zero.

Why the honest number wins the room

The plant CFO has seen the ₹18 Cr slide before. They also know what the operations team actually delivers. When your number lines up with their private estimate, you stop being a vendor and start being someone they can staff a pilot with.

Run the numbers on your plant

Two modes — general savings, or TPM/OEE-shaped inputs. Both compute honestly. Both cite their sources inline.

Open the ROI calculator