Ask three suppliers what an assembly line costs and you will get three numbers that cannot be compared, because each has drawn a different boundary around the word "line". One has quoted conveyors. One has quoted conveyors, stations and controls. One has quoted all of that plus installation, commissioning and training. The cheapest is usually the one that excluded the most, and you find out during commissioning.
This guide breaks the cost down the way we estimate it internally — per station, plus the line-level items that sit on top — so you can budget realistically and read competing quotes on a like-for-like basis.
Start from the station, not the line
A production line is a series of stations joined by conveying. Cost the stations first, because that is where most of the money and nearly all of the variation sits. A manual assembly station with a bench, bins and a torque tool is a fraction of the cost of a station that presses a bearing, measures the seating depth and logs the result against the part serial.
The useful question is not "what does a line cost" but "how many stations, and what does each one have to prove?" Once you can answer that, the number stops being a guess.
Indicative cost bands per station
These are order-of-magnitude bands for planning in India, not quotations. They exclude the part-specific tooling, which can move any of them.
| Manual assembly station | Bench, bins, lighting, basic tooling, air. Roughly ₹1.5–4 lakh depending on ergonomics, ESD requirements and the tooling mounted on it. |
|---|---|
| Manual station with verification | Adds torque/angle monitoring or part-presence sensing and a pass/fail interlock. Roughly ₹4–10 lakh. |
| Semi-automatic station | Operator loads, machine performs the operation — press-fit, riveting, screwing, dispensing — with monitoring. Roughly ₹8–25 lakh. |
| Automatic station | Automatic feed, operation and unload, no operator in the cycle. Roughly ₹20–60 lakh. |
| Robot cell station | Robot, tooling, guarding, safety system and integration. Roughly ₹25–80 lakh depending on payload, reach and what the robot has to do. |
| Test or leak-test station | Instrument, sealing tooling, fixturing, data logging. Roughly ₹10–40 lakh; the sealing tooling is usually the variable. |
The spread inside each band is not padding. A press-fit station that only has to push a bush to a stop and one that has to hold seating depth to ±0.05 mm and prove it on every part are different machines wearing the same name.
The seven things that move the number
1. Cycle time against takt
Takt is available time divided by demand. If your takt is 90 seconds, most operations fit in one station. At 25 seconds the same work needs parallel stations, faster actuation or a different process — and cost rises faster than the time falls. Halving cycle time rarely doubles cost; it often more than doubles it. Before you specify an aggressive takt, check the line balancing arithmetic — the constraint is usually one station, not the whole line.
2. How much quality proof sits inside the line
The single biggest swing. A line that assembles is cheaper than a line that assembles and proves. Force and depth monitoring, torque-angle curves, vision inspection, leak testing and per-part data logging each add cost at the station where they sit — and each removes a source of customer complaints. This is a commercial decision, not a technical one: what does a defect reaching your customer actually cost you?
3. Variants and changeover
One part number is straightforward. Four variants sharing a line means quick-change nests, recipe handling on the PLC, poka-yoke to stop the wrong variant being built, and a changeover method that does not eat an hour. Expect variant handling to add meaningfully to both the station cost and the engineering time.
4. Conveying and the line layout
Conveying is usually 15–30% of a line. Belt and roller conveying is the economical end; pallet and free-flow costs more but lets stations run at different rates without stopping each other. If your stations have genuinely different cycle times, free-flow is usually cheaper overall than the buffer stock and downtime you avoid.
5. Automation level, chosen station by station
Automating uniformly is the most expensive way to build a line. The station that pays back is usually the one causing rework two operations later, not the one that looks worst. We have talked customers out of automation more than once and kept the relationship because of it.
6. Safety architecture
Guarding, interlocks, light curtains and a safety relay or safety PLC are not optional extras, and they are not free. Budget for them from the start — machine guarding designed in during engineering costs a fraction of guarding retrofitted after an audit or an incident.
7. Traceability and data
Barcode, QR, DMC or RFID identification with per-part result logging and an export to your MES adds cost at every station that records something. In automotive and EV work it is usually a customer requirement rather than a choice, so establish it early — retrofitting traceability into a finished line is expensive.
What sits on top of the stations
| Engineering | Layout, line balancing, station design, electrical and pneumatic design, safety risk assessment. Typically 10–18% of the project. |
|---|---|
| Line controls | Line PLC, HMI, network, interlocking between stations, andon and data collection. |
| Installation and commissioning | Rigging, erection, alignment, hook-up, loop checks, safety validation, trials. Typically 8–15%. Frequently excluded from cheap quotes. |
| FAT and SAT | Running the line with your parts before dispatch and again on your floor, against a written protocol. |
| Documentation and training | Drawings, BOM, schematics, program backups, manuals, SOPs, operator and maintenance training. |
| Ramp-up support | Supported production over the first shifts until the rate is stable. Often the difference between equipment delivered and output achieved. |
A worked example
Take a six-station manual-plus-verification line for an automotive component, 600 parts per day on two shifts, one variant plus a second added later.
- Four manual stations with part-presence and torque verification
- One semi-automatic press-fit station with force and depth monitoring
- One end-of-line test station with data logging
- Belt conveying between stations with a small buffer before the test
- Line PLC, andon, traceability by DMC read at station one
Stations and conveying land the equipment cost in the middle of the bands above. Engineering, controls, installation, commissioning, FAT/SAT, documentation and ramp-up add roughly 35–45% on top of the equipment. That ratio surprises people, and it is exactly the part that cheaper quotes leave out.
How to make competing quotes comparable
Send every supplier the same scope statement, and insist each quote states clearly:
- Station count and what each station does
- The cycle time being quoted against, and at what OEE assumption
- Whether installation and commissioning on your site is included
- What FAT means, with whose parts, and who signs it
- Whether the safety risk assessment and guarding are included
- Which bought-out makes are assumed — PLC, drives, pneumatics, sensing
- What documentation and program backups are handed over
- What ramp-up support is included, and for how long
Any quote that will not answer those eight points is not a quote, it is a number. Our RFQ guide has a checklist you can send with the enquiry.
Buying a line in stages
Most lines do not have to be bought at once, and a line designed to be phased costs materially less in year one without costing more overall — provided the phasing is decided at design time rather than discovered later.
What makes phasing work:
- Design the layout for the final configuration. Reserve the floor space, the conveyor length and the utility drops for the stations you will add, even if they stay empty for two years. Retrofitting a station into a line laid out without room for it usually means moving everything downstream.
- Buy the conveying and the control backbone once. The conveyor, the main panel, the network and the safety architecture are the things that are disruptive to extend. Size them for the final station count.
- Start stations manual where the volume allows. A manual station at a well-designed bench, on the same pitch and at the same working height as the automatic station that will replace it, converts cleanly later.
- Standardise station interfaces. The same footprint, the same mounting pattern, the same electrical and pneumatic connection, the same signal exchange with the line controller. Then a new station is a plug-in, not a project.
- Agree the phase-two price at phase one. Get the supplier to quote the later stations and the conversion work while you still have commercial leverage, with a validity or escalation basis written in.
What does not work is deferring the constraint. If one operation is the bottleneck at your day-one volume, automating it later does not help you now — and a line built around a bottleneck you intend to fix later tends to have a layout that makes fixing it awkward.
What the line costs after it is installed
The purchase price is the smaller number over a line's life. Worth estimating before you choose between a manual and an automatic configuration:
- Direct labour. Operators per shift × shifts × loaded annual cost. Usually the largest running cost, and the one automation trades against.
- Consumables and wear parts. Tooling, locating pins, grippers, belts, seals. Ask for a list with expected life and price at quotation stage — it is a reasonable thing to ask and a revealing one.
- Maintenance. Planned hours plus an allowance for unplanned. Lines built from locally available standard components cost less here than those built around imported specials.
- Energy. Air is expensive. A line that runs continuous vacuum or has unregulated leaks can cost more in compressed air than in electricity.
- Quality cost. Scrap, rework and the escapes the line does not catch — which is where error-proofing pays for itself.
A line that is ₹20 lakh cheaper to buy and needs one extra operator per shift on two shifts is not cheaper. Run both numbers over five years before deciding.
Where the money is usually wasted
- Over-specified accuracy. Accuracy is expensive and rarely the thing that fails. Specify what the next operation actually needs.
- Uniform automation. Automating stations that were never the constraint.
- Buying capacity you will not use for three years. A line designed to be extended costs less than a line designed for year-three volume on day one.
- Skipping the layout study. A few lakh of study regularly saves a multiple of that in equipment nobody needed.
If you have a part drawing and a target output, we can put an indicative range against it. Send it through the engineering assessment and an engineer comes back within one working day.