How to Track Yarn Wastage Per Machine in a Weaving Unit

Yarn is typically 60–70% of a weaving unit’s cost base. Wastage of 1–2% of that yarn is the difference between a good month and a bad one. And yet, in most weaving units, wastage is reported at unit level, monthly, after the fact. This post walks through how to track yarn wastage at the level it actually happens — per machine, per shift — and why that changes the economics.

Why per-machine matters

Two looms running the same design can show very different wastage profiles. The reasons are usually one of:

• Mechanical condition: a slightly bent reed, a worn sley, a tension issue in the warp let-off. Each causes warp breaks; warp breaks cause wastage.
• Supervisor habits: how aggressively a supervisor restarts after a break, how carefully they check selvedge, how often they clean the loom.
• Yarn batch issues: a particular yarn lot loaded onto a particular beam may have a defect that only that loom sees during this beam.

If you only have unit-level wastage numbers, all three of these causes look identical. You see the unit running 4% wastage and you do not know why. With per-machine data, the conversation shifts: “Loom A-103 is at 5.5% on the same design A-102 is at 2.1% on. Why?” That question has a fixable answer.

The four wastage types

Lumping all wastage into one number is the second mistake. Different types of wastage have different causes and different fixes:

1. Warp wastage

Warp ends broken or removed during weaving — usually visible as short lengths of warp yarn on the cropping. Causes: poor sizing, mechanical defects (reed, harness), tension issues, low-quality yarn. Tracked in kilograms per beam or as a percentage of warp consumed.

2. Weft wastage

Weft yarn lost in setup, mid-run breaks, or end-of-run overruns. Lower volume than warp wastage but not negligible — high-RPM water-jet looms can lose meaningful weft to startup waste alone. Tracked in kilograms per beam or per shift.

3. Idle wastage

Yarn consumed (or scheduled) during loom downtime — ramp-up, ramp-down, idle running. Often hidden because it doesn’t show as scrap; it shows as sub-target production. Tracked by comparing actual production hours against scheduled hours.

4. Off-grade wastage

Takas graded B or reject — yarn that produced fabric, but fabric the customer won’t pay full price for. Subtler than direct yarn loss but often larger in rupee terms. Tracked at grading.

A unit that reports “4% wastage” without splitting these is reporting an opinion, not a number.

The variance threshold approach

The simplest practical method: each design master carries target wastage percentages, calibrated from history. Actual wastage is compared against target on every doffing entry. When the variance exceeds a threshold (typically 1.5–2 percentage points), a flag raises.

Target setting

Targets are not aspirational — they are what your typical good loom produces on this design under normal conditions. Set them too low and every loom flags; set them too high and the system never catches anything. The discipline is to:

1. Collect 30–60 days of historical wastage by design and machine.
2. Take the median (not the average — averages hide outliers).
3. Add a small allowance (10–20%) for normal variation.
4. That number is the target.

Threshold tuning

Variance thresholds depend on the wastage type:

• Warp wastage: variance > 1.5 percentage points → flag.
• Weft wastage: variance > 1.0 percentage point → flag.
• Off-grade: variance > 5% of taka count → flag.
• Idle: efficiency < 88% → flag.

These are starting points. Tune them down once your floor is calibrated; otherwise you’ll get alert fatigue.

Same-shift vs end-of-month

The biggest economic gain is not better tracking — it is faster tracking. Wastage caught at month-end is wastage you have already paid for. The arithmetic:

A loom running 4% warp wastage when target is 2%, on a typical mid-size unit producing ₹5 crore of fabric per month with ₹1.25 crore of yarn cost, loses approximately ₹10,000 per loom per month at that wastage level. If the same loom keeps running like that for two months before the report surfaces it, ₹20,000 per loom is gone. On 150 looms, eight or ten with this profile is ₹1.6–₹2 lakh a month of avoidable loss.

The gain isn’t from a 1% reduction in average wastage. The gain is from cutting the time-to-detection from 30 days to 1 day. The lost yarn at 4% in shift 1 is unrecoverable; the yarn at 4% in shift 2 is preventable.

How MobiOffice does it

The mechanical setup, in MobiOffice:

1. Design master holds target wastage per type (warp / weft / off-grade). Tunable per design.
2. Variance threshold is unit-level with per-design overrides. Set during the AS-IS / GAP / TO-BE phase.
3. Mobile doffing entry carries actual wastage at each doff. Supervisors enter meters produced and any defect notes; the system calculates wastage from the design recipe.
4. Wastage-by-machine view shows current shift, current day, last 7 days. Filters by design, loom, supervisor, shift.
5. Variance flags raise in the dashboard the moment a threshold is crossed. Production manager and owner see them on their phones.
6. Wastage voucher posts to accounts at end of shift, automatically. No separate Tally entry, no end-of-month adjustment.

If you want to see this running on a real floor, the wastage by machine screen shows the actual interface. For the broader picture of how production data flows from doffing to inventory to accounts, see the production page.

Three operational notes

1. Calibrate quietly for 30 days before flagging anyone. New tracking systems generate noisy alerts initially. Tune the thresholds, don’t broadcast variances, until your data has settled.
2. Pair the flag with a check action. A wastage flag without a defined response (check the loom, escalate to maintenance, change the supervisor’s brief) creates alert fatigue. Define the response when you set the threshold.
3. Watch supervisor patterns, not just loom patterns. When the same supervisor’s looms consistently exceed target across designs, that’s a coaching conversation, not a maintenance ticket.

The honest pitch for live wastage tracking isn’t that it makes wastage 1% lower. It’s that it makes wastage visible to the only people who can do anything about it, in time for them to do something. That’s where the rupee gain comes from.

For the dedicated solution page covering this workflow end-to-end, see wastage tracking software. The glossary entries for warp, weft, and sizing cover the related vocabulary. For the broader cost framing, the Tally + Excel vs integrated ERP cost comparison puts wastage savings in context.