Ethicon Inc., part of the Johnson & Johnson family of companies, designs and manufactures advanced surgical instruments and medical devices for minimally invasive surgery. Located in Cincinnati, OH, the company provides a range of surgical products and technologies as well as a full range of professional medical education and services to its customers.
With growing complexities and variety of its products coupled with the need to keep historical data as required by the FDA’s regulations, the engineers at Ethicon was faced with a time consuming process to maintain, update and synchronize the design requirements, actual inspection, and tolerance analysis information for their products. This information needed to be accessible, traceable, up-to-date, consistent, compliant and transparent across different levels within the company and its suppliers.
Before implementing the TADM-System, the engineers used Excel spreadsheets to store the aforementioned information and to perform all non-complex, linear tolerances, stacks for quick turn-around analysis. For complex, non-linear tolerance stacks and tolerance stacks with moving parts, advanced tolerance analysis applications were used. As a result, the engineers had to manage discrete sets of information in isolated places and/ or under different applications which made the work process less inefficient for the engineers.
Some of the critical facts and needs for the engineers were:
- Each engineering team at EES can work on one or more projects and each project which is a typical 1-2 year long project in which many tolerance stacks are created. For each project, the engineers spend estimated 100+ hours to maintain and update these tolerance stacks. EES has multiple engineering teams and each team is working on multiple projects concurrently so actual hours estimation could be a much higher number.
- When frequent changes are made to the design, the engineers had to go through a manual and as such a time consuming process to check stacks to determine if those still are “good” or meet requirements.
- Just with any other manual process, it was easy to make mistakes and hard to catch errors. There were cases in the past that some required dimensions for the tolerance stacks were missing from the drawing revisions. Since these drawings are modified frequently, such mistakes can happen and when it happened, it took weeks or months for the engineers to discover and it was very costly each time.
- The engineers always spent great efforts managing non-conforming parts from suppliers. They realized that inspection data could be more streamlined to tackle this problem and to help them cut costs by relaxing non-critical tolerances. However, to take this advantage, the inspection data needs to be conformed into the existing tolerance stacks. This is a very time-consuming effort.
Ethicon implemented the TADM System in a phased implementation over the last 5 years, with these following key benefits to be expected and measured.
- Little or no learning curve.
- Drastic reduction in manual effort
- Advanced, sophisticated database driven process to augment standardization, conformity and error correction among other things.
- Availability of advanced features e.g. inspection data management and what-if analysis helps engineers manage non-conforming requirements and detecting impacts at much faster pace.
- Level of confidence in all levels from initial design to production since the requirement is driven by highest of quality demanded.
Since the TADM-System was implemented, all tolerance analysis information has been organized, standardized, made consistent, up-to-date and easily accessible to the engineers and the suppliers. The results from the TADM System implementation are shown as follows.
- The system uses Excel as its interface which is very intuitive and very easy to use.
- Multiple tolerance stacks created were by this system including complex tolerance stacks created by Enventive tolerance analysis software.
- With the implementation, there is no need to perform updates whenever there is new drawing revision. All tolerance stacks get updated automatically; therefore, saving 100+ engineering hours.
- The system has automatically identified several drawing issues before being finalized.
- Inspection data from suppliers can now be stored and retrieved to plug into any existing tolerance stacks. Design data and inspection data can then be compared side by side so that non-conforming dimensions can be found quickly. If dimensions need to be modified, The What-If feature provided by the TADM-System can allow the engineers to immediately understand the impacts of the modifications on all existing tolerance stacks. Therefore these nonconforming dimensions can be managed quickly effectively.
- Many engineers use the application to manage all product tolerance analysis. Since all data is stored in a central database, the engineers can concurrently obtain, store and update the tolerance analysis data more effectively and accurately.