How to calculate and reduce WIP in Cutting, Sewing, Washing, and Finishing of Apparel Industry
What is WIP?
WIP stands for work-in-progress or work-in-process, that is describing the amount of product in the production process between sections. WIP report telling the number of unfinished products in a different process to be finished. Raw material and Finished goods are not counted as WIP, because these items are not in the production process. Excessive WIP in production inventory creates lots of problems and makes a mess. So the target of WIP is to keep as minimum as possible. Here we discuss how to Calculate and Reduce WIP in Apparel Industry.
Where we see WIP in the Garments Industry
WIP term is used in the different manufacturing processes; like other manufacturing processes, this term is also used in the garments production process. In the garments industry, WIP calculates for Cutting, Sewing, sewing washing, washing process WIP, and finishing processes WIP; washing and finishing are finishing the stage in the garments industry when customers chase delivery. If we can calculate WIP properly, we can reduce too.
How to reduce WIP in the Garments industry
Reducing WIP in garment industry is crucial for improving efficiency, reducing lead time & minimizing costs. Here are some strategies to reduce WIP in garment industry:
- Single pieces production flow instead of batch-wise production
- Line balancing and removing bottlenecks from the process
- Proper planning, layout, and machine allocation.
- Keeping the same production flow everywhere.
- Use a kanban card in the production process.
- Apply JIT (Just-in-time) process
- Keep organized production process.
How to Calculate WIP in the Garments industry
- WIP of Cutting section: Cutting is not a very complex process, generally, less bottleneck is there. So cutting WIP may not be a big factor in the garments industry. For example, If the cutting section has cut a total of 4546 pieces for a style or PO and 1875 pieces have been issued to the sewing department already. So, the cutting section WIP is 2671 pieces.
- Cutting section WIP = Total cutting quantity – Total quantity sent to sewing,
- = 4546 – 1875
- = 2671
2. Sewing Line WIP: WIP can be calculated line by line in the sewing section, every sewing line has a different style to produce. The sewing line should be smooth for high production and minimal WIP. For example, To Line# X total of 3500 pieces have been loaded for style# or PO A, and a total of 2800 pieces are out from the line. Sewing line WIP is 3500-2800 = 700 pieces
Sewing Line WIP = Total pieces loaded to the line – Total pieces sewing production/ output
3. Washing process WIP: Garments washing is a very critical process, washing standards and shade appearance have to get approval from the buying house. #If we send 5000 garments for the washing process so far, and received washed garments 3190 pcs till now. So the Washing process WIP is= (5000-3190) = 1810 pcs. Washing process WIP= Total quantity sent for washing – Total received from washing
4. Finishing section WIP: Garments finishing have so many processes and quality becomes a big factor here. Finishing WIP increases for only different quality problems in the different processes like high workmanship defects, measurement deviation, and mismatch shade requirement. Finishing section WIP = Total received from sewing – Total pieces packed; = 47985- 28775= 19210 pcs
How to report WIP in a Garments industry
We can use Microsoft Excel to make WIP reports for the garments industry. Here I am giving a section-by-section WIP report on the garments industry. All we have to calculate WIP by Style and PO wise, as every PO has a certain shipment date.
WIP Reporting for Cutting Section:
| Cutting Qty | Input Date | Day Input to Sewing | Ttl Input to Sewing | Input Balance/Cutting WIP |
| 18000 | 9-Jun-18 | 790 | 16900 | 1100 |
| 3242 | 7-Jun-18 | 1300 | 2920 | 322 |
| 2786 | 10-Jun-18 | 1050 | 2580 | 206 |
| 21873 | 22-May-18 | 980 | 20080 | 1793 |
| 11798 | 4-Jun-18 | 1280 | 11000 | 798 |
| 3444 | 9-Jun-18 | 2110 | 2300 | 1144 |
| 3425 | 9-Jun-18 | 1950 | 2050 | 1375 |
| 4386 | 9-Jun-18 | 2000 | 2790 | 1596 |
WIP Report for sewing Section:
| Total input to Sewing | Day output of sewing | Total output of sewing | Sewing Line WIP |
| 18520 | 480 | 17955 | 565 |
| 960 | 3100 | 142 | 818 |
| 2950 | 175 | 2786 | 164 |
| 1370 | 19700 | 1200 | 170 |
| 2208 | 1150 | 2019 | 189 |
| 1485 | 1790 | 50 | 1435 |
| 1620 | 2015 | 1410 | 210 |
| 3311 | 415 | 3220 | 91 |
WIP report for Washing:
| Total sent for washing | Today’s washing quantity | Total Washing quantity | Washing WIP |
| 3323 | 45 | 3,232 | 91 |
| 3371 | 3100 | 142 | 3,229 |
| 3531 | 0 | 2,786 | 745 |
| 3110 | 19700 | 2,173 | 937 |
| 2500 | 920 | 2100 | 400 |
| 1485 | 85 | 1285 | 200 |
| 1429 | 2015 | 1,410 | 19 |
| 3920 | 415 | 3,600 | 320 |
WIP report for Finishing:
| Total input to Finishing | Today pack quantity | Total pack quantity | Finishing Line WIP |
| 4250 | 750 | 3,000 | 1,250 |
| 3620 | 900 | 2000 | 1,620 |
| 2896 | 820 | 1,150 | 1,746 |
| 2790 | 870 | 2,200 | 590 |
| 3658 | 1380 | 2370 | 1,288 |
| 2875 | 1400 | 2275 | 600 |
| 3145 | 1200 | 2,145 | 1,000 |
| 2985 | 1050 | 1,380 | 1,605 |
Final thought, Calculate and Reduce WIP are in the same line. The WIP calculation is very easy, reduction is not big deal too.
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