# IPC/WHMA-A-620 Class 1, 2 or 3 Selection Assessment > Source: https://netray.co/tools/whma-a-620-class-selection-assessment > Publisher: Netray (netray.co), AI and integration engineering for ERP and manufacturing systems. > Section: Free Tools ## Short answer A scored questionnaire on end use, failure consequences, environment and service life that indicates which workmanship class a harness most likely needs. ## Category quality ## Industry Wire Harness & Cable Assembly ## Audience - Quality engineer - Estimator - Design engineer ## Tool **Kind:** assessment **Questions:** #### What does the harness serve? **Help:** Pick the closest application type. **Options:** ##### Consumer or general-purpose product **Score:** 0 ##### Commercial or industrial equipment **Score:** 1 ##### Transportation, medical or critical industrial equipment **Score:** 2 ##### Aerospace, defense, life support or similar **Score:** 3 #### What happens if the harness fails in service? **Options:** ##### Minor inconvenience, product still works or is easily replaced **Score:** 0 ##### Product stops working, repair needed, no safety issue **Score:** 1 ##### Costly downtime, warranty cost or customer safety exposure **Score:** 2 ##### Injury, loss of mission or loss of life is possible **Score:** 3 #### Is uninterrupted performance required? **Options:** ##### No, intermittent use is fine **Score:** 0 ##### Mostly continuous but short outages are tolerable **Score:** 1 ##### Continuous operation expected **Score:** 2 ##### Must perform on demand without fail **Score:** 3 #### What is the operating environment? **Options:** ##### Benign indoor, stable temperature **Score:** 0 ##### Indoor industrial, some dust or vibration **Score:** 1 ##### Outdoor, washdown, wide temperature or heavy vibration **Score:** 2 ##### Extreme heat, cold, shock, fluids, vacuum or radiation **Score:** 3 #### What is the expected service life? **Options:** ##### A few years, replaceable product **Score:** 0 ##### Five to ten years **Score:** 1 ##### Ten to twenty years **Score:** 2 ##### Longer, or inaccessible after installation **Score:** 3 #### Can the harness be inspected or replaced after installation? **Options:** ##### Easy to access and replace **Score:** 0 ##### Replaceable with moderate effort **Score:** 1 ##### Difficult to access **Score:** 2 ##### Not serviceable (sealed, embedded or remote location) **Score:** 3 #### What does the customer contract or drawing require? **Options:** ##### No workmanship standard called out **Score:** 0 ##### IPC/WHMA-A-620 called out without a class **Score:** 1 ##### Class 2 called out **Score:** 2 ##### Class 3, a space addendum or a customer-specific requirement above Class 2 **Score:** 3 #### Does the product or customer require lot traceability and records? **Options:** ##### No **Score:** 0 ##### Date codes only **Score:** 1 ##### Lot and operator traceability **Score:** 2 ##### Full serialization with material certs and inspection records **Score:** 3 #### What test and inspection depth does the application justify? **Options:** ##### Visual check only **Score:** 0 ##### 100% continuity **Score:** 1 ##### Continuity plus hipot, crimp monitoring or pull sampling **Score:** 2 ##### Full testing plus process verification, FAI and source inspection **Score:** 3 #### What cost trade-off is the customer willing to make for reliability? **Options:** ##### Price is the main driver **Score:** 0 ##### Balanced price and quality **Score:** 1 ##### Reliability prioritized over price **Score:** 2 ##### Reliability is non-negotiable **Score:** 3 **Bands:** #### Points toward Class 1 (general electronic products) **Min:** 0 **Max:** 34 **Verdict:** Your answers describe a product where function is the main requirement and cosmetic imperfections or brief failures are tolerable. Class 1 criteria usually fit, but confirm with the customer drawing. **Recommendations:** - Confirm the class in writing on the drawing or PO rather than assuming - Keep basic crimp height and pull checks even at Class 1 - Document your acceptance criteria so rework decisions are consistent - Revisit if the product is later sold into a more demanding market #### Points toward Class 2 (dedicated service electronic products) **Min:** 34 **Max:** 67 **Verdict:** Continued performance and extended life are required, and uninterrupted service is desirable but not critical. Class 2 is the common choice for industrial, commercial and many transportation harnesses. **Recommendations:** - Plan 100% continuity test and a documented crimp and pull verification routine - Train operators and inspectors to Class 2 acceptance criteria - Quote with Class 2 inspection time rather than Class 1 - Ask the customer whether any circuits need stricter treatment #### Points toward Class 3 (high performance electronic products) **Min:** 67 **Max:** 100 **Verdict:** Continued high performance and failure on demand are unacceptable, or the environment is severe. Class 3 criteria apply, and aerospace or space programs may add further addenda and customer requirements. **Recommendations:** - Build Class 3 inspection, certified operator training and recordkeeping into the quote - Check whether a space or military addendum or customer standard also applies - Plan first article inspection and tighter process control on crimps and solder - Confirm traceability and certificate of conformance requirements before pricing ## Content **Intro:** IPC/WHMA-A-620 defines acceptance criteria for cable and wire harness assemblies in three classes, and the class changes inspection effort, training and price. This assessment helps frame which class an application most likely needs before you quote or design. **Sections:** #### How to use the assessment **Body:** Answer each question for the finished product the harness goes into, not for the harness in isolation. Score reflects the end-use consequences: safety, failure impact, environment, service life, and what the contract already says. The result is guidance. The final class is set by the customer or the product design authority, and the assessment helps you prepare a defensible conversation. #### What the three classes mean **Body:** The standard describes Class 1 as general electronic products where the primary requirement is function of the completed assembly. Class 2 is dedicated service electronic products where continued performance and extended life are required and uninterrupted service is desired but not critical. Class 3 is high performance electronic products where continued high performance or performance on demand is critical, equipment downtime cannot be tolerated, and end-use environments may be harsh. Many requirements are common across classes, with tighter criteria at higher classes. #### Reading the result **Body:** Treat a result near a band boundary as a prompt to ask the customer. If the contract states a class, that governs. If your result points higher than the contract states, raise it because later field failures can become your problem even when the drawing was silent. Remember that class is chosen for the acceptance criteria, and that a harness can meet a higher class without being required to. #### Common mistakes **Body:** Assuming Class 2 by default without asking. Quoting Class 2 labor and then being held to Class 3 inspection. Applying one class to every harness in a mixed program when only some circuits are critical. Treating the class as a certification rather than an acceptance criterion applied by trained inspectors. Not stating the class on the traveler, which leaves operators guessing. **Cta:** If class, inspection plans and test records live on paper travelers, we can talk through carrying them as structured data in your ERP or quality system. **Faq:** #### Who decides which IPC/WHMA-A-620 class applies? **Answer:** The customer or design authority decides, usually on the drawing or purchase order. The supplier should not choose a lower class on its own. If the class is not stated, ask in writing before quoting. #### Is Class 3 always more expensive? **Answer:** Generally yes, because tighter acceptance criteria require more inspection, stricter process control, more rework and documentation. How much depends on the design and the equipment. Quote each class on its own inspection and training assumptions. #### Can one harness have more than one class? **Answer:** Customers sometimes call out different classes for different circuits or features on a drawing. If so, state the mapping clearly on the traveler so operators and inspectors apply the right criteria to each. #### Does this replace reading the standard? **Answer:** No. This is a decision aid built on the standard's class definitions. Use the current revision of IPC/WHMA-A-620 for acceptance criteria and train inspectors to it. ## Search terms ipc whma a 620 class 1 2 3, which ipc class do i need, wire harness workmanship class, ipc a 620 class selection, class 3 cable assembly requirements, whma a 620 classes explained, cable assembly acceptance class, harness quality class --- Talk to an engineer: https://netray.co/contact?intent=erp_ai | Machine catalog: https://netray.co/agent/catalog.json