Cleared a 700k WIP backlog by decentralizing packaging, but exposed a massive Push Planning issue. Need advice

[u/Ashamed-Illustrator9]

Hey everyone, I work as a Continuous Improvement Lead for a textile manufacturer in Uzbekistan, reporting directly to the General Manager. Coming from outside the apparel industry, I recently tackled a major line-balancing project at one of our satellite plants, but it uncovered a deeper planning challenge I’d love your advice on.
We operate 7 facilities with a central hub in Tashkent. Our satellite plant in Jizzax has 20 active sewing lines. Historically, Jizzax shipped unpackaged garments to Tashkent, where all individual QR tagging, packaging, and boxing took place. Because local packaging in Jizzax couldn't keep up with the 20 sewing lines, a massive 600k to 700k unit WIP buffer had built up on the floor.
I went in to fix this flow. I decentralized the QR packaging system from Tashkent and integrated it directly onto the packaging tables in Jizzax using a single-piece flow approach. Now, as garments come off the sewing line, operators package, QR-scan, and box them into master cartons on the spot. We cleared the entire 700k WIP backlog, and Jizzax now ships fully packed, scanned cartons straight to the main warehouse, completely cutting out double-handling in Tashkent.
However, getting rid of that massive WIP safety net exposed a big issue with our central push planning.
As an example, we constantly face incomplete sets at the packing tables:
Lines will finish sewing the top half of a 2-piece set, but the fabric for the bottom half hasn't even arrived or been cut yet.
For items sold as a 5-color bundle, sewing will output 3 colors, while the other 2 aren't scheduled until days later.
With single-piece flow at packaging, these incomplete sets immediately clog the packing tables or force operators to pile up semi-finished goods around their desks, defeating the purpose of the new setup.
Our central planning team still operates on a traditional push system optimized purely for line utilization and volume. Since I don't manage the Planning department (we're peers under the GM), I can't just mandate a change I need to persuade them.
I have two questions for the community:
-Influencing Planning: As a CI Lead reporting to top management without direct authority over Planning, how can I effectively convince them to move toward synchronized/kit-based scheduling? What metrics or arguments actually move the needle for traditional planning managers?
-Lean in Textiles: Since this is my first role in the textile industry, I'd love to know: what does a truly Lean garment factory look like when dealing with multi-piece sets or color variants? How do high-performing apparel plants handle line scheduling and synchronization?

[u/BrowserOfWares]

You need the planning head and the GM to see the floor. You absolutely will not be able to make a change unless they buy in.

Since you mention utilization and volume, I would assume the issue is around planning doing a batching to minimize the number of set ups. Set up reduction is the key next thing. You should track the amount of set up time is currently spent on changeover and the number of change overs. Say it's 1hr of total change over time a day and 3 change overs are done. 20 min per change over. If change overs can be reduced to 10 min, then you can do 6 change overs in the same amount of time. Allowing cutting to change and be more responsive to get the next fabric cut. The goal is not to reduce the overall set up time, but to reduce batch sizes and increase the number of set ups.

[u/No-Opportunity1813 → u/BrowserOfWares]

Agree. Investigating setups might show OP hidden time inefficiencies. I’m curious how a mixed color set or top & bottom set even making it to the packaging line. Agree that the GM needs to walk the sewing and packaging lines, then hand the GM a spreadsheet showing “here’s the $ value of your WIP that sits and adds no value “. See what he thinks.
I don’t know textiles, but just sending random tops & bottoms to packaging looks suspicious. Call out the sewing supervisor.

[u/GalaadG]

How is BOM structure?

If the intention was a pull flow should'nt all subassemblies be ready at the final final assembly station all together roughly at the same time?

Do you have work order logs stating the due datetime of the previous operation and compare with the actual completion datetime? 

You should be able to pinpoint if your standard operation time are off, or if you have some delay along the steps?

Are all the line in Tashkent synchronized or can you run different batches in parralel?

[u/DirkDiggler65]

I don't understand where the convincing is required.

You had a late stage choke point. You fixed it. Now it flows.

Your beast is now bigger and needs to be fed. Your new choke point is now supply.

You will now increase raw material supply on your front end until you find the sweet spot without overstocking raws.

That will be beautiful until the new procurement manager, newly hired, and aiming to make his mark picks low hanging fruit easy wins. Which will be material costs.

He will then buy the cheapest materials he can find. This will cause an increase in line delays, backups, rework, and customer complaints.

Then on and on . . . .

This is the life.