How to reduce the production cost of my device?

A lot of this boils down to quantity and capex. A production cost is set for a specific amount of products you will make. The more you make, the more efficient you can set up your equipment and the more products you can make within a certain timeframe. Increasing capex, like investing in tooling and jigs, can also lower your production cost but of course there is a return on investment to take into account. Talk to your suppliers. In the end everybody needs to make a fair living so including suppliers in technical discussions and applying best practices often creates win-win situations.

Be critical with the specifications you set for your product. A good reminder here is “as loose as possible, as tight as needed”. This applies to details on your final drawing but originates from the initial use cases. For example: if your product has to be waterproof, does this mean it could catch a drop of rain or will it be submerged for long periods of time?

Do not underestimate assembly. Easy to assemble products require less time thus are cheaper. Design for assembly (DfA) does not only focus on time but also on first time right. Reducing the chance of mistakes, reduces rework and lowers your overall cost as well. Poka Yoke parts or snap fits instead of glue are just a few ways to go about this.

The same goes for testing. Determine when and what will be tested and how you will manage quality throughout your process. Reworking a fully assembled product after end of line testing can take a lot of time. Testing parts early on or easy to reach subassemblies in between can avoid unnecessary time unscrewing covers or disconnecting cables.

Optimise your parts. Since raw material is a part of your cost, reducing that amount can add up in higher production volumes. But be aware of the pitfall since optimization will increase engineering effort and could require more simulation and testing. There’s always a difficult balance between engineering cost and product cost savings.