Since each wire/cable manufacturer has its own specialization and processes, significant performance variations can be found despite using the exact same product specification. Tests performed by Lectromec on the same wire specification from multiple manufacturers have found a 2:1 performance variation on key electrical and mechanical properties. Clearly, not all parts made to the same specification perform the same despite what some distributors say.
Just as should be done on most other product types, it is important to have a set of vendors that you can trust. Identifying a reliable set of wire/cable vendors can help to improve your overall product reliability. The following article provides a review of the process and benefits of maintaining a wire/cable vendor whitelist.
Creating a Whitelist
How many times does an engineer need to review performance requirements of a data cable? How much time is wasted reviewing specifications for the exact same cable that is used across an entire product line?
The basic idea of a whitelist is to have a set of reviewed and accepted vendors/products that conform to performance thresholds. By creating a catalog of acceptable wires and cables, the time necessary for selection and procurement is significantly reduced. Furthermore, because the same cable is used across multiple product lines, any issues can be traced to one or two sources. Ideally, if the wire/cable is on the whitelist no issues will occur, but if they do, this helps to accelerate the failure analysis and risk mitigation strategy.
How to Approach
There are two possible ways to approach the creation of a whitelist. Each has its benefits and drawbacks and is entirely dependent on the organization’s needs.
#1) Sample Evaluation
The first approach starts with creating a list of vendors currently in use by your organization, organized by specification used, and begin a limited scope testing program. In doing so, the performance can be determined vis-à-vis the product specification and performance needs. From this, the initial list can be culled to a few select vendors and a trusted whitelist is created.
The benefit from this approach include:
- Starting from an existing use basis accelerates the project and keeps a tighter project scope
- A limited number of changes to design drawings and installation procedures.
#2) Requirements Based
The second approach is to gather the specific requirements from each product line. The requirements are reviewed and grouped to reduced overall number of wire/cables needed by the organization. Vendors are then selected, evaluated, and, if the product performs well enough, is placed onto the whitelist.
Visually these wires look the same, but testing found that one of these is twice as likely to fail in elevated temperature applications. Creating a curated whitelist of wire/cable vendors can ensure only the best components make it into your equipment.
There are a couple notable benefits to this approach:
- Reduced breath of wire/cable inventory needs. Since multiple product lines will use the same wire/cable, fewer varieties will need to be kept in inventory.
- This will make it possible to benefit from quantity discounts with larger purchases of the same wire/cable.
Sustainment
As with most projects, once the initial effort is taken on and completed, there is a legitimate concern that the output will be not be maintained or remain current. To this end, it is recommended that a third-party be assigned responsibilities for the whitelist. Doing so helps to mitigate the risk of the whitelist management becoming lost in the daily requirements of a single individual.
Furthermore, as a third-party has unbiased, this provides an incentive to identify the best products and continue to improve the whitelist product line. Lastly, a third party such as Lectromec can offer specialized support and expert knowledge into each one of the product categories.
The return on investment for a well-maintained whitelist is clear. Product engineers can focus on product improvements and not spend time searching through endless specification sheets only to select the same wire/cable that was placed on another product. Procurement is made easier. Lastly, the annual cost for maintaining the overall whitelist is relatively low.
Summary
The creation of a wire/cable whitelist can provide a good return on investment for your organization. This reduces the costs associated with wire/cable selection and reduces the number of problems with unverified vendors. To find out more about how you can help your organization with the development of a whitelist, contact Lectromec. Our wire/cable experts can help you realize operational, performance, and design improvements faster than you would expect.
Michael Traskos
President, Lectromec
michael.traskos@lectromec.comMichael has been involved in wire degradation and failure assessments for more than a decade. He has worked on dozens of projects assessing the reliability and qualification of EWIS components. Michael is an FAA DER with a delegated authority covering EWIS certification and the chairman of the SAE AE-8A EWIS installation committee.