Line balancing and bottleneck removal

Learning objectives

• Distinguish bottleneck from system constraint on a sewing line.
• Balance work using takt, pitch and precedence, not average cycle alone.
• Improve throughput without over-loading a single operator.

Problem and CTQ

When WIP accumulates and hourly output misses plan, work content, skill, uptime and variation are mismatched. Balance the line to takt with an explicit constraint plan.

DMAIC path

• Validate SAM and observed cycle time.
• Compare takt, pitch and capacity; map precedence, WIP, blocking/starving, skills, machine needs and defects.
• Distinguish the current bottleneck from the system constraint.

Improvement choices

• Split/combine work, method improvement, helpers and skill transfer.
• Attachment/machine allocation, pitch/WIP control and constraint protection.

Control plan

• Balance efficiency, line efficiency, pitch attainment, bottleneck cycle, WIP, FPY, overtime and throughput.
• Daily 15-minute pitch review with defect and downtime overlay.

Garment-factory example

A T-shirt line at 68% balance loss sits on side-seam. A helper plus a new folder on collar-attach cuts side-seam cycle by 12% and lifts line efficiency from 62% to 71% with FPY unchanged.

Common mistakes

• Balancing on average cycle only.
• Moving work between operators without matching skill or training.