Manufacturing KPIs beyond OEE

Improving a process only counts if you can measure it. That's what KPIs are for.

OEE gets most of the attention, and rightly so. It's probably the most widely adopted manufacturing KPI in the world. But on its own it won't tell you everything, and some of the most useful measures sit just underneath it.

There's an international standard for manufacturing KPIs, ISO 22400. You don't need to memorise it, but it's worth knowing it exists, especially if you're comparing figures across sites or systems.

Here are the ones I'd make sure you can measure.

First-pass yield

The percentage of output that passes every quality check first time, with no rework.

It tells you how capable your process really is. A line can have decent OEE quality rate and still be quietly reworking 10% of what it makes. First-pass yield exposes that.

You'll also hear "first time through". It's subtly different depending on who defines it, so agree the definition before you compare numbers.

Scrap rate

The percentage of output that's waste.

Don't just count the material. Scrap also throws away the machine time, labour and energy that went into making it. In food and process industries, the related measure of yield, raw material in against good product out, is often the single biggest profit lever.

Cycle time

The time it takes to produce one unit, against the target.

Cycle time variation across shifts and operators is one of the clearest signs of an unstandardised process. It also feeds the real-time schedule, so the system can estimate when an order will actually finish.

Changeover time

The time it takes to switch from one product to the next.

In high-mix, low-volume manufacturing, changeovers are often the biggest constraint on throughput. Measuring them accurately is the first step to reducing them.

OTIF

On Time In Full. The percentage of orders delivered complete and on the date promised.

This is the KPI that connects shopfloor performance to the customer. You can have great OEE and still miss deliveries if the wrong things were made at the wrong time. OTIF keeps everyone honest.

MTBF and MTTR

Your maintenance KPIs.

• MTBF (mean time between failures): how often equipment breaks down.
• MTTR (mean time to repair): how quickly you fix it.

Together they tell you whether your reliability is improving and where maintenance effort is best spent. More in MES functionality: maintenance.

Getting the data right

Every one of these KPIs depends on accurate, granular data. Calculated from end-of-shift entries, they'll be wrong in ways that look perfectly plausible.

The best approach:

• Capture counts, states and stops automatically from the equipment.
• Calculate KPIs in one system, from one set of data, so production, quality and maintenance aren't each producing their own version.

That's a big part of what MES/MOM does.

Don't measure everything

One word of warning. It's tempting to build a dashboard with 40 KPIs. Nobody will look at it.

Pick a small number that connect to what the business cares about: usually output, quality, cost and delivery. Make sure they're trusted. Then use them every day, in the morning meeting, to decide what to fix next.

Which KPI does your leadership team ask about most, and do you trust the number?