The Slowest Machine Isn't Always Your Bottleneck

Ask a plant team where their bottleneck is and most people will point to the machine with the lowest rated speed. That's a reasonable first guess, and it's often wrong.

Rated speed vs. effective speed

The nameplate speed is what a machine can do while it's running. What matters for output is its effective rate: rated speed multiplied by the share of time it's actually available.

Take two machines:

The filler is the slower machine on paper. But the labeler stops so often that it delivers less over a shift. The labeler is the real constraint.

Why it matters

If you misidentify the bottleneck, you spend money in the wrong place:

• Speeding up a machine that isn't the constraint adds capacity the line can't use.
• Buying a faster filler in the example above wouldn't add a single unit per shift, because the labeler would still hold the line back.
• Fixing the labeler's stops would lift output for the whole line.

How to find your real bottleneck

You need three numbers for each machine:

1. Rated speed, in units per minute.
2. Failures per shift, meaning how often it stops.
3. Average time to repair, meaning how long each stop lasts.

From the last two you get availability, and from that the effective rate. The lowest effective rate is your bottleneck. Recheck it after any change, because once you fix one constraint, another machine takes its place.

Bottleneck first, then everything else

Once you know the real constraint, the next decisions get clearer. You can see whether an upgrade at that machine pays back, whether an accumulator on either side of it would protect it, or whether it's a maintenance problem rather than a capital one.

The LineIQ calculator works this out for every machine on your line, flags the true bottleneck, and shows what fixing it is worth.