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Why Mixed Lines Are Slowing You Down – And How to Fit IT


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Ever wonder why your line never quite hits the numbers you expect?


When you mix products with different speeds on the same line, fast items get trapped behind slower ones. This bottleneck creates what I call Performance Drag—the hidden loss in throughput caused by mismatched cycle times.

The good news: you can measure it, and you can win it back. That’s where the Decouple Equation comes in.

 

The Decouple Equation at a Glance

The Decouple Equation gives you a quick way to calculate how much throughput you’re losing—and how much you can gain—by separating mixed-product lines.

At its core, the math is straightforward:


System Gain

System Gain (%) = (∑ Separated Hourly Outputx / ∑ Shared Line Hourly Output x – 1) * 100  

Where:

  • Separated Hourly Output = 3600 / CTx​

  • Shared Hourly Output = 3600 / CTavg * Px ​

  • Px​ = Product share of total orders

  • CTavg = ∑(Px * CTx)


This tells you the percentage of throughput you’re currently leaving on the table.

Individual Line Gain

Line Gainx(%) = (Separated Outputx / Shared Outputx − 1) × 100

This helps pinpoint which product lines suffer most from being mixed—so you know where to separate first.

For more detailed versions of these formulas and their usage, download the full whitepaper.

 

A Quick Example

Imagine three products (A, B, C) running together:

Product

CT (sec)

Share of Orders

A

60

30%

B

120

40%

C

140

30%

  • Shared Line Output: 34 units/hour

  • Separated Output: 115.7 units/hour

That’s a 247% throughput gain simply by decoupling!

Looking at individual lines:

  • A gains 500%

  • B gains 125%

  • C gains 157%

Even when demand is batched by order share, Product A still improves significantly, while Products B and C expose hidden inefficiencies.

 

When to Use the Decouple Equation

  • Flow separation decisions → Test if separating lines is worth it

  • Automation analysis → Spot drag caused by slow vs. fast cycle times

  • Kaizen events → Quantify opportunities for lean layouts

  • Shift planning → Forecast output under different product mixes

 

Bottom Line

Performance Drag is costing you more than you realize.

The Decouple Equation turns that hidden loss into measurable opportunity.

Whether you’re planning automation, restructuring lines, or running a Kaizen event, this simple approach shows you exactly how much more you could produce—using the resources you already have.


Want the full math, technical appendix, and advanced pairwise model? Download the full whitepaper here.



 
 
 

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