Medical device manufacturing process: from order to dispatch

The stages below follow one typical product: a titanium cortical bone screw, turned from bar on a Swiss-type sliding head lathe, colour anodised by a vendor, laser marked, cleaned and packed in a cleanroom, then sterilised by a contract steriliser before release. A plant moulding single-use devices or assembling electromedical equipment has different operations, but the records it has to keep follow the same order.

For each stage, the useful question is not only what happens but what record it leaves on the batch. Those records are what QA reviews before release and what an auditor reads later.

The process at a glance

1. 1Customer orderPart, revision, quantity, sterile or non-sterile, and delivery date.
2. 2BOM and routingBar, pouches, labels and the operations with their checks, fixed at the released revision.
3. 3Material planningNeeds compared with accepted stock by lot and open purchase orders.
4. 4Procurement and incoming inspectionBar received by heat number with its mill certificate; pouches and labels by lot.
5. 5Work order releaseThe batch is planned on the lathe and material is issued by heat number.
6. 6MachiningFirst article approval, then turning, thread whirling and deburring, with counts and scrap logged.
7. 7In-process inspectionThread, head and length measured against tolerance, with the instrument.
8. 8Finishing and packingAnodising at the vendor, laser marking, cleaning and cleanroom pouch sealing.
9. 9SterilisationSent to the contract steriliser on a challan and returned with its certificate.
10. 10Final inspection and releaseFinal checks, batch record review, release or hold.
11. 11DispatchReleased batches picked and shipped with the batch number on the delivery note.

What happens at each stage, and what it records

1. Customer order

The order comes from a device brand owner or a distributor, for a part number, a revision, a quantity, and whether the screws are supplied sterile. The record holds all four and the delivery date. If the customer later revises the drawing, the order shows which revision this batch was made to.

2. BOM and routing

The BOM lists the titanium alloy bar, the sterile barrier pouch, the label and the instructions for use. The routing lists turning, thread whirling, deburring, anodising at the vendor, laser marking, cleaning, packing, sterilisation and final inspection, with the checks required at each. The revision released to the batch is fixed on it. The guide to multi-level BOM management covers revision handling in more depth.

3. Material planning

Requirements from open orders are compared with accepted stock by lot and with open purchase orders. Titanium bar can have long lead times, so a shortage report that names the batch it will stop, and when, gives purchasing time to act. Material still in quarantine should not count as available.

4. Procurement and incoming inspection

Bar arrives with a mill certificate giving the heat number and chemistry. Incoming inspection checks the certificate against the specification and the bar diameter, then accepts or holds the lot. Pouches and labels are received by supplier lot. The record holds the supplier, the heat number or lot, the quantity, the certificate reference and the result.

5. Work order release and material issue

The batch is planned on a lathe according to its capacity and released when material is ready. Stores issues bar by heat number. From this point, every count and measurement on the batch is linked to that heat.

6. Machining

At setup, the first screws off the machine go through first article inspection against the drawing before the batch runs. During the run, the operator logs good counts and scrap with a reason against each operation. The record shows what each operation made, by operator and time, which is what lets QA confirm the batch quantity reconciles from bar to finished screw.

7. In-process inspection

Thread major and minor diameter, head diameter, overall length and drive recess are checked at the frequency the inspection plan sets, using thread gauges, micrometers and a vision measuring system. Each value is recorded with the batch, the inspector, the time and the instrument. A value out of tolerance holds the batch until QA records rework, use as is, or reject. Checking here, rather than only at the end, stops tool wear from spoiling a whole batch; the article on reducing rejection by inspecting at the operation explains why.

8. Anodising, marking, cleaning and cleanroom packing

The machined screws go to an anodising vendor on a challan and come back against it, where they are counted and colour checked. The record holds the quantity sent and returned, any short or rejected quantity, the vendor's certificate reference and the charge. Back in the plant, each screw is laser marked with the lot number, cleaned to the validated cleaning process, and packed in pouches in the cleanroom. Process parameters for the pouch sealer, such as temperature, pressure and dwell time, are recorded for the batch, as is the cleanroom the packing took place in.

9. Sterilisation

Packed screws go to a contract steriliser, usually for gamma irradiation or ethylene oxide, on a challan. They come back with a sterilisation certificate for the load. The record links the batch to the steriliser's load reference and certificate, and counts what came back against what went out.

10. Final inspection and batch release

Final inspection checks a sample against the plan: labelling, pouch seal integrity and any dimensions the plan repeats. QA then reviews the batch record: material certificate, issued lots, counts by operation, inspection results with instruments, dispositions, vendor and steriliser returns. If it is complete and every result is within limits, QA releases the batch. A batch with an open hold or a missing entry cannot be released.

11. Finished goods and dispatch

Released batches are received into finished goods by batch and picked against the order. The delivery note and invoice carry the batch number, which is where any later complaint or field action will start. Stock that is packed but not yet released stays separate and cannot be picked.

What to record and control at each stage

Where the process usually breaks

• At receipt, when the heat number on the mill certificate is not carried onto the stores record, so the trace has a gap from the start.
• At inspection, when the value is written down but the instrument is not.
• At a hold, when out-of-tolerance parts are set aside without a recorded decision, and some find their way back into the batch.
• At the vendor, when anodised or sterilised parts are not counted against the challan and a short return is found at packing.
• At release, when the batch record is compiled from paper and QA finds missing entries after the people involved have moved on.

How is one batch traced back from dispatch?

If a surgeon's complaint reaches the brand owner with a lot number, the trace runs backwards: delivery note to released batch, batch to its sterilisation load and anodising return, then to its counts, operators and inspection results with the instruments used, and finally to the heat number and mill certificate of the bar. The same records run forwards too: if a heat of bar is found to be wrong, every batch and shipment it reached can be listed. When each stage left its record on the batch, this is a lookup. When the records are on travellers and sheets, it is an investigation.

How FleekERP records each stage

In FleekERP the bone screw batch is one work order, and each of the eleven stages is a step on it. Stores receives bar and pouches by lot with incoming inspection and issues them to the batch by lot. Operators record counts and scrap from their phones with their name and the time, QC records measured values against nominal and tolerance with the instrument through quality control, a failed check holds the batch until it is dispositioned, and anodising and sterilisation run as vendor operations on the routing with their challans. The batch record is assembled from those entries and released before dispatch, and the invoice syncs to Tally or Zoho. FleekERP is not validated for ISO 13485 or 21 CFR Part 11; that validation is the manufacturer's. The medical devices industry page shows the same flow from the plant's side.

How the process differs by plant type

• Implant and instrument machining: bar by heat number, deep routings on Swiss-type and multi-axis machines, first article at every setup, and finishing and sterilisation often outside.
• Single-use disposables: resin lots, moulding or extrusion, assembly and packing in a cleanroom, large batches, and ethylene oxide sterilisation by load.
• Electromedical equipment: many component lots per unit, PCB assemblies, functional testing, and usually a serial number on each finished unit.
• Precision parts for device makers: the customer's drawing and inspection plan, part-level records sent with each delivery, and the customer's own audits of the plant.