Connectors are frequently selected based on purchase price without fully considering the costs linked with using them. What do connectors really cost?
Have you ever purchased the lowest-priced item, only to find out that the cost to use or own it was much more than you expected? Quite often that is the case with connectors: They are frequently selected based on purchase price without fully considering the costs linked with using them.
All connectors, whether wire-terminated or PCB-mounted, have additional costs associated with them. Some costs are readily known while others are hidden.
Total connector costs can generally be broken down into three categories: Known costs; costs that can be determined with some effort; and costs known only after use and experience.
Category 1: Known Costs
Known costs include:
- Component piece price including list, negotiated, EAU (estimated annual usage), or special quantity. Companies often outsource fabrication of harnesses and printed circuit boards, including the assembly of the electrical connectors. When this happens, even the purchased cost of the connector may be hidden.
- Special packaging. This is sometimes needed for compatibility with application equipment or handling, such as bulk, reels, tubes, trays, tape, etc.
- Shipping cost. Standard or expedited, domestic, or international
- Tooling cost for custom-engineered connectors. This cost may be outright or amortized in the connector piece price.
Category 2: Costs Determined with Some Effort
- Application cost. All connectors, whether terminated to wire or mounted on printed circuit boards, have application costs. Some of the application costs include:
- Wire termination labor costs. Wire cutting and stripping, terminal crimping, soldering, welding, screw clamping, poke-in, terminal insertion into housings, insulation displacement (IDC) termination, etc.
- Wire termination application tooling costs. Wire cutting and stripping machines, crimping presses, contact application machines, IDC machines, hand tools, insertion tools, extraction tools, etc.
- PCB-mounted connector labor costs. Physically pick, orient, and place the connectors in the proper location. It may be hand placement or many levels of automation.
- PCB-mounted connector tooling costs. Fixtures, feeding mechanisms, pick-and-place machines, robots, end effectors, press-fit presses, etc. Because connectors are generally considered to have odd form factors, they may require custom tooling to handle them.
- Tooling maintenance costs. In addition to the application machines themselves, there is also the cost of what is classified as expendable tooling. This is tooling that contacts the connectors and wears over time. It consists of crimpers, anvils, stripper blades, feed fingers, guides, etc. Expendable tooling is usually the responsibility of the end user to purchase and replace. Expendable tooling life can be very short for some types of connectors.
- Documentation costs. Most connector users will have some documentation costs related to drawings, specifications, assembly instructions, quality control requirements, etc. These costs can be reduced by using information and specification from reliable connector suppliers.
- Testing costs. Specific application testing, regulatory agency testing, environmental testing, etc., can be costly if using connectors in undocumented or new applications. Occasionally connector suppliers may provide this testing at no cost to promote their products.
- Approvals cost. May be required for regulatory agency, safety, etc. If the connector has not been “recognized” by the approval agency, additional testing of the end device will likely be required.
- Scrap cost. This is always present but seldom accounted for in estimates. This includes set-up scrap, qualification samples, typical human-related flaws such as wire placement in crimps, etc.
- Rework cost. Rework, repair, or replacement of connectors can be time consuming and very costly in terms of labor and materials.
- Recycling/segregation/disposal/recovery cost. The emphasis on sustainable products and manufacturing means that increasingly, connectors and their respective packaging need to be end-of-life processed. This can be very costly and needs to be considered in addition to the initial connector cost.
- On-site inventory cost. Based on order quantity, delivery schedule, physical volume, etc. Inventory costs can be reduced by connector suppliers having just-in-time (JIT) deliveries.
Category 3: Costs Known Only After Use
This category is potentially the most costly in the long term. These costs include:
- Sorting costs: The costs associated with sorting and separating good connectors and end devices from bad.
- End-device replacement or scrap cost: Costs incurred due to connector-caused non-repairable or non-cost-justified repairs of the end device.
- Product delay-to-market costs: If the selected connector does not function properly during engineering testing of the end device, procurement and testing of alternate choices may delay the product launch date.
- Warranty costs: The costs due to failures experienced by the end customer of the device
- Business cost: The cost of potential loss of business, market share, and reputation in the event of a failure may be difficult to determine but can be catastrophic in terms of business. On the other hand, a very reliable and user-friendly connector may help promote and sell the end device.
Determining the total connector cost may require some effort, but the rewards are potentially significant.
Consulting with suppliers that have competent technical support staff and well-engineered design guides can result in proper selection of product, shorter design cycles, less redesign, better reliability, and an overall reduced installed cost.
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Ed Reynolds, currently a principal consultant at APEX Electrical Interconnection Consultants, has more than 48 years of experience with most aspects of interconnection products. He has worked on a wide range of products, including switches, fiber optics, fasteners, magnet wire terminations, sockets, modular jacks, high-speed I/Os, flex circuits, MID (molded-in-devices), and many surface-mount products. He has experience in the computer, peripheral, telecommunications, automotive, consumer durable, consumer electronics, motor, transformer, small appliance, and power tool industries. Reynolds held the title of principal engineer and director of development engineering at AMP.