Even products with relatively quick design cycles and short stays in the market deal with part obsolescence.
Long design periods along with long durations in service or in production simply increases the chance that one or more parts will become obsolete.
Designing systems with part obsolescence in mind helps. Working with suppliers to select parts with many sources, with long-term plans to produce, and with long term commitments, all may help. Even then, companies change priorities, go out of business, or simply discontinue the part you need.
Planning for obsolescence is difficult.
Yet you can prepare contingency plans to execute when you learn of an impending loss of part availability. There are short term and long term solutions available, by planning for the necessary actions you keep as many options available as possible.
Short term solutions
- Find an alternative part.
By far the simplest solution if a suitable part exists. The part may have slightly different capabilities, yet if a subset of functions along with the form factor meets your system’s needs, using a ‘close enough’ part may provide a viable solution.
2. In some cases, you may have to re-engineer the subsystem or circuit board to accommodate the replacement part.
3. One-time buy. Buy all the available parts when you anticipate a part is becoming obsolete. Of course one of the issues is storage and the various costs of inventory, yet if you are able to buy sufficient quantity of parts it may meet remaining production and spare parts needs. Or, the action may provide time for a longer term solution to become viable.
4. Aftermarket or custom build the part. Find another supplier willing to make replicates of the obsolete part. Check on patent and licensing as the original manufacturer may retain rights to the design. This is risky and often expensive as even minor changes to the structure or assembly of the part may cause differences in its operation in your system.
5. Up-rate a similar part. In some cases, a less robust part may have the basic functionality, yet not designed to function well at the expected stress levels of your system. It may be possible to find a suitable part that may increase the system failure rate under a high-stress situation, yet meet the system’s needs in most cases.
Given the variability of part robustness, in some situations, this approach may involve expensive testing and sorting operations to find suitable robust parts.
6. Salvage existing parts. A junk yard is a great place to find parts for an old model vehicle. When a system fails, not every part has failed thus making it possible to find the specific parts you need to meet production or spare parts requirements.
Of course, the salvage operation may damage parts or the old parts may have sufficiently aged to be of little value.
This one takes some planning as you need to retain a stockpile of retired or failed systems and store them to protect the individual parts from damage or deterioration.
Long term solutions
- Redesign the system or subsystem with obsolete parts.
For circuit boards, this may involve using a custom ASIC or further integration thus avoiding the need for specific parts. In some cases using new materials or manufacturing processes reduce the need for the obsolete parts.
2. Use a regular refresh strategy. Plan on updating and refining the platform on a regular basis. Rather than try to keep a specific design in production for 20 years, plan to redesign, possibly adding functionality, while maintaining backward compatibility.
This requires careful design of the original system to permit the various elements to continue to evolve while still providing the same basic functionality.
3. Monitor and forecast part obsolesce as early possible.
Having even a few months more lead time provides you with more options to address the disappearance of part availability. Proportional hazard modeling and data mining approaches, as well as many others, attempt to provide as much lead time before part obsolescence as possible.
There isn’t one solution for every part obsolesce notice you receive.
Having a range of viable options available reduces the risk of production or system shutdowns pending suitable parts.
How does your organization deal with this issue? Add a comment and add any other options that you know about to the list.
Identifying Parts Obsolescence Early (article)
Part Selection Process and Reliability (article)