Pitch Time: Two Meanings and How to Use Each

Pitch time means two different things in garment factories: the average work content per operator used for line balancing, and the lean interval for moving a pack of finished goods. Formulas, examples and when to use which.

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Pitch time is a term you will hear in two different ways. Both are useful, but they are not the same number. Say which one you mean.

Meaning 1: average work per operator (line balancing)#

In garment line balancing, pitch time is the ideal amount of work each operator should carry:

Pitch time=Garment SMVNumber of operators\text{Pitch time} = \frac{\text{Garment SMV}}{\text{Number of operators}}

A T-shirt with SMV 12.0 on a line of 40 operators has a pitch time of 12.0 / 40 = 0.30 minutes. If the work were perfectly divided, each operator would have exactly 0.30 minutes of work per garment.

Using control limits#

Perfect division is rare. Many engineers set a band around the pitch time and try to keep each operator's load inside it. A common approach:

  • Upper limit: pitch time × 1.15
  • Lower limit: pitch time × 0.85

For a pitch time of 0.30 minutes, the band is 0.255 to 0.345 minutes. An operator loaded with 0.40 minutes is a likely bottleneck; one with 0.20 minutes has spare time. The 15% figure is a planning convention, not a standard; choose a band that suits your lines.

Theoretical operators per operation#

Operators for an operation=Operation SMVPitch time\text{Operators for an operation} = \frac{\text{Operation SMV}}{\text{Pitch time}}

An operation with SMV 0.75 and a pitch time of 0.30 needs 2.5 operators. You then round this by combining or sharing operations. See line balancing.

Meaning 2: lean pitch (pack-out interval)#

In lean manufacturing, pitch is the time interval for moving a standard pack of finished product:

Pitch=Takt time×Pack-out quantity\text{Pitch} = \text{Takt time} \times \text{Pack-out quantity}

With a takt time of 30 seconds and a carton of 20 pieces, pitch is 600 seconds (10 minutes). Every 10 minutes, one carton should leave the line and new work should be released. This helps supervisors see quickly whether the line is on schedule, instead of waiting for the end of the hour.

Which one to use#

Situation Use
Allocating operations to operators Pitch time = SMV / operators
Setting material release and pickup intervals Lean pitch = takt × pack quantity
Checking whether demand can be met Takt time

Worked example: line pitch with bands#

A shirt has SMV 22.0 and the line has 44 operators.

  • Pitch time: 22.0 / 44 = 0.50 min
  • Band: 0.425 to 0.575 min
Operator Load (min) Status
1 0.48 Within band
2 0.61 Above band: bottleneck risk
3 0.39 Below band: spare time
4 0.52 Within band

Move some work from operator 2 to operator 3 if they use the same machine type, or give operator 2's manual elements (trimming, marking) to a helper.

Use the pitch time calculator for both definitions.

Frequently asked questions#

Is pitch time the same as takt time? No. Takt time comes from customer demand. Line pitch time comes from the garment SMV divided by operators. When the line is sized correctly for demand at standard pace, the two are close, but they answer different questions.

Should helpers be included in the operator count? Include everyone who carries a share of the garment's work content. If helpers do work that is part of the SMV (trimming, marking, folding), count them; if not, leave them out and be consistent.

What if an operation is much longer than pitch time? Split it between several operators, or look for a method change that reduces its work content. See line balancing.

What if many operations are much shorter? Combine short operations on the same machine type, keeping the sequence practical for bundle flow.

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