Ensuring Product Quality in a Distributed Manufacturing Model
Point of View | 19 January 2017
The Quality Challenge
Quality is a priority in manufacturing, and many quality control processes have been developed and applied to the industry to make sure objects produced meet level of specifications established at the design stage on characteristics such as mechanical strength or dimensional accuracy. A centralized production makes it simple to control tooling as well as the items produced.
Regarding distributed production, quality management is not an easy task. The main challenge, and by no means an insignificant one, is to reach in each affiliated manufacturing facility the same quality which is set in the engineering office. How do we ensure consistent quality over various places of production?
Industrial Quality Management Processes
To ensure consistent quality on the spares we have produced, it is essential to be particularly strict about the manufacturing conditions.
Quality management in the manufacturing industry is widely based on the Ishikawa Diagram, including the 5-M factors – for Material, Method, Man Power (or Mind Power), Machine and Measurement. This diagram enables us to identify potential factors affecting the production quality. It is well known for being used by Toyota, whose quality management is a model for the manufacturing industry.
Performing a strong control over those 5-M factors leads to a rigorous quality management and industrial standardization.
If quality management within a specific factory is an industrial issue in itself, yet it is an even more complicated challenge in a distributed production organization. How to strictly control specific manufacturing parameters when you’re not in situ?
To solve this problem, we elaborated a manufacturing process which enables us to maintain a tight control over our production. We adjusted the 5-M factors’ method to ensure consistent quality on our distributed production.
Our own version of the Ishikawa diagram tailored our specific requirements
Our providers all use the exact same machines and follow a rigorous process for calibrating the machines to ensure identical production results at every location. The calibration process is built to avoid any human interpretation or error, and to facilitate the work of our providers. The key characteristics of the machines are monitored regularly so that before any unacceptable deviation occurs the calibration process is reiterated.
We use qualified models of selected brands of 3D printers, recognised for their product reliability and consistency over time.
When digitizing a part to make it available in a virtual inventory, we proceed to industrialization and production tests using specific plastics materials such as high quality ABS, HIPS, PA, POM or PP. These materials have been previously qualified so that we know exactly their technical specifications and have developed accordingly specific production processes to optimize their use. In our distributed production network, we supply our providers with this very materials, in order to ensure that the parts produced will be exactly the same as the ones we engineered and tested with regards to solidity, dimensions and aesthetic aspects.
Manpower & Mind Power
To ensure best operation, skills and focus are the two key factors we must develop at our suppliers. First of all, we train our providers so they strictly apply our quality processes. To be part of our network, they go through a set of qualification tests. Once they’re qualified with Spare Parts 3D and started to perform production, we ensure regular training on printers’ maintenance and calibration as well as on quality check that is executed on every part. Second, we use financial incentive as a powerful means to encourage our suppliers to keep a focus on quality. Whatsoever we also strive to deploy processes in our distributed manufacturing network preventing human error to ensure a maximized consistency of the production quality.
Our quality management includes statistical process control over the production made by our providers. This system of quality control uses statistical methods to continuously assess the production process deviation towards standard and then alert and fix the printers to ensure consistent quality over every item manufactured. This includes a direct remote monitoring of the 3D printers especially with regards to production temperature, which is a determining factor in the production by 3D printing. Once produced, all the parts are visually inspected by our providers, which might trigger once again a re-calibration of the printer used.
A Challenge Successfully Met
Our business and technical model being different than those of the traditional manufacturing industry, we had to adapt quality management to the specificities of distributed production. In order to reach and ensure high consistent quality, we keep the same demanding approach widely used in the industry, and apply it to our production model. To maintain quality even when production is decentralized, we decided to maximize our control over key elements (material supplying, production instructions, machines used), thus quality of the 3D printed part remains constant over time and locations.