When a capacitor or resistor is obsolete or on allocation, it’s easy for a distributor not to bid, but it leaves buyers with big gaps. Debbie Rowland explains how Charcroft tackles the problem.
Distribution can be measured on many metrics. Buyers can look at statistics for on-time delivery, quality and cost, but perhaps there is an even more important metric that buyers should consider: the number of parts for which a distributor provides no-bid at all on a quotation.
Of course, there can be valid reasons why a distributor would no-bid, such as not being franchised by the manufacturer of a proprietary part, or the part falling outside of its available linecard. But the fact that a capacitor or resistor is obsolete or on allocation should not be a valid reason for a no-bid.
No-bidding is certainly the easiest option for a distributor, especially for relatively low-value parts such as capacitors or resistors, but it is far from easy for the buyer. It means that the buyer must re-send the quotation to other suppliers and complete the bill of materials from multiple sources, which in turn increases the accounting overheads. This process may take days and still not lead to the buyer being able to achieve on-time delivery.
Finding alternatives
There is another approach that distributors could use, but it requires time, knowledge and effort. At Charcroft, for example, it is a matter of policy to automatically check for alternatives, not only for obsolete passives, but also for parts which are on long lead-times. This approach could become increasingly important as the industry begins to see allocation on some capacitors and resistors.
For distributors, the first step in avoiding a no-bid is to identify the part. If the BoM includes a part number, manufacturer name and a full product description, this can be fairly straightforward. Sometimes, there is only a part number, which means that the distributor will need to check ordering guides on legacy datasheets to confirm the product description.
Once the part has been identified, the next step is to translate the product description into a part number from a different manufacturer. For example, an obsolete Syfer 8123Z0500104KX multilayer ceramic capacitor can be directly replaced by a Charcroft VK20BY104KA or Kemet C052T104K5X5Cx as well as by mil-spec part numbers. All of these alternatives are currently in production and may provide a viable solution.
Asking questions
Unfortunately, not all substitutions are quite as simple and it is then that the real work begins for those distributors with the expertise to undertake it. The key is to understand every detail of the specific application and find any area of flexibility. Perhaps a relaxation of tolerance from one to five per cent would be acceptable? Or maybe the parts only really need to be specified for a maximum operating temperature of 85 rather than 125°C. In other applications, it may be possible to use a different voltage, or even a totally different type of capacitor, which can match the performance characteristics of the original part.
While these questions will typically need input from engineering colleagues, they do provide the basis for finding alternatives. Providing answers also means that buyers avoid the frustrating and time-consuming process of filling in the gaps when distributors go for the easy option of not bidding on a difficult part.