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Reliability Testing on Electronic Products in China: Don’t Skip It

Reliability Testing on Electronic Products in China: Don’t Skip It We have worked with many companies that have designed an electronic product and had it manufactured in China, yet they tend to have a common blind spot: running reliability testing on electronic products. Why do electronic product importers overlook reliability testing?Importers tend to think that doing great design and working with the right EMS supplierwill save them a lot of trouble. And that’s true, it certainly does.They often know about the need to know where the critical components come from and to have access to the source code, about the need to visit factories, and about the need for inspections before shipment.They sometimes know about the importance of setting up the right testing stations, doing a pilot run (aka ‘PVT’ for consumer electronics), and some other process engineering work.However, there is one blind spot that I see consistently: most of them have never thought of doing reliability testing. What is reliability testing for electronic hardware?The idea is to get the product to function in extreme conditions (temperature, humidity, vibrations…), in order to see if/when it fails. Ideally, the tests should mimic the normal use of the product.The best time to run such tests is typically in the pre-production stage, once all the components (including the battery management system, any firmware, etc.) that will be used for mass production are available. The units to test should be made in the exact same way mass production will be manufactured. It is often called HALT (Highly Accelerated Lifetime Testing):HALT is applied to the initial product testing stages prior to production and its primary objective is to highlight failure modes and weaknesses in the design so that the design can be modified and improved to eliminate any weaknesses found.The general approach often looks like this: What type of issues can be avoided thanks to reliability testing?Here are three examples of issues that are not that uncommon in electronic products:Some components soldered on the PCB board move (and get disconnected) due to vibrations in transportationCapacitors have micro-level defects that only cause issues when the product is exposed to humid ambient airA battery stops operating normally at a temperature that would be considered normal (say, 5 degrees in Siberia)Reliability tests can help you catch these issues before it is too late!These tests often catch design issues that would seldom be detected with inspections after production (actually, those issues often become obvious once the product is in the customer’s hands!) What is a common reliability testing program for electronics?Let’s take an example, based on a relatively simple product with a mechanical element but no wifi/bluetooth/4G connection. A good testing plan might look like this.a) Environmental simulationsHigh temperatureLow temperatureCycling at different levels of temperatureSalt sprayb) Mechanical simulationsDrop test (without packaging)Vibration test (without packaging)c) Lifetime simulationsMany on/off cycles for the motorPressing the buttons many timesd) Packaging suitabilityDrop test (with packaging)Vibration test (with packaging) How deep can it go?If you purchase millions of pieces of a particular model, you will certainly want to go more in-depth with the testing, and a good laboratory can assist you in this.For example, when it comes to batteries (a product we know pretty well), here are some examples of points that can be assessed:External short-circuit (cell)External short-circuit (battery)Free fallThermal abuse (cells)Crush (cells)Over-chargingForced discharge (cells)Mechanical testsDesign evaluation — Forced internal short-circuit (cells)

When To Do a Random AQL Inspection vs. Full Check 100% of the Goods

First, let me get one thing out of the way: not all batches need to be checked.If a manufacturer has great systems and processes, and if they have a history of complying with your quality standard, there is usually no reason to send quality inspectors to their factory.Similarly, if you can easily return the whole batch and it can be reworked quickly, you probably don’t want to spend resources on checking whether they did as promised.Now, let’s assume you do want confirmation of product quality.Should you perform a random AQL inspection or a 100% check?When to only check a random sample?By default, most buyers try to keep the volume of work low, by doing a random inspection.And, in the vast majority of cases, for consumer goods, they follow the ISO 2859-1 (or ANSI/ASQ Z1.4) standard, set an inspection level, and set AQL limits.The classic scenario goes as follows. A quality inspector (working for the buyer, or working for a QA agency appointed by the buyer):Goes to the supplier’s factoryCounts the presented quantity, picks boxes & products at randomChecks the products and their packing for visual defectsConfirms specifications are metPrepares a report that includes a pass/fail resultWho needs a random AQL inspection?If you work with multiple suppliers and your quality standard accommodates 2-3% of defective goods, this is probably what you need to do. When to do a 100% inspection?From experience, I would point to three reasons some importers want a piece-by-piece check:The cost of delivering defective products is very high – it is worth spending more time to sort out all the bad pieces. For example, empty shampoo bottles that will go on an automated line (which might be stopped for hours because of one deformed bottle).There is a strong suspicion that a batch has quality issues and the supplier hasn’t done a good QC job — this is a classic after a first inspection failed and there was no reaction. Note that, if you know what the issues are, this is a focused check (sorting the goods by checking for 1 or 2 specific issues) and it can be done faster than looking for all types of issues on all pieces.There is a risk that good products get replaced by bad ones after inspectors are gone — sorting good pieces into cartons that are immediately sealed makes this swapping game harder to play. All this has a cost. Over time, importers try to get their key suppliers to self-inspect more effectively. However, this is not realistic with all suppliers.For example, many Japanese apparel brands still check all the pieces they buy in other Asian countries…Should the 100% inspection be done in the supplier’s factory?If the quantity is low and the product is simple, it can be done in the factory that made the goods.If the work takes 5 or more man-days of work, though, the bill gets significantly higher and it might not be realistic.What is the alternative? Having the batch of products delivered to another facility where the goods are placed on a line, checked one by one by trained operators, and (if accepted) are repacked immediately. It is more efficient and can be much cheaper, than sending people out.One major advantage here is speed and simplicity. In many cases, what buyers want to avoid is this scenario:Too many defectives are found, the batch is rejectedThe supplier doesn’t communicate about their reaction plan or pretends they only found 1-2% of defectivesAn inspector comes in again, same findings, and another rejectionThe supplier keeps playing that game until the buyer can no longer wait and has to request shipmentThe difficulty, here, is to convince the supplier to:Deliver the batch to another facility before receiving full paymentAccept not to get paid for the goods that were sorted out as defectives in a ‘black box’ process they couldn’t witnessIf these obstacles can be waived, it can be an excellent approach. Another benefit is, some labeling and branding elements can be affixed on the goods in that other facility, and the supplier will not know the distribution channel, the selling price, and so on.Does this make sense? Have you seen this in practice, and how did it go?

What are the audit categories?

Audit classification.1. Classification by Audit Enforcement Subject2. According to the nature of the executing subjects of audit activities, audit can be divided into three categories: government audit, independent audit and internal audit.3. According to the classification of financial auditing, auditing can be divided into four categories: operation auditing, performance auditing, financial statements auditing and information technology auditing.4. According to the classification of audit contents, China generally divides audit into financial audit and economic benefit audit.5. Auditing can be divided into three categories: pre-audit, in-process audit and post-audit, according to the classification of audit implementation time relative to the economic business of the auditee.6. According to the technical model adopted, auditing can be divided into three types: account-based auditing, system-based auditing and risk-based auditing.7. According to the place of execution, it can be divided into two kinds: submitting audit and on-site audit.

What are the contents of the audit procedure?

Types of audit procedures(1) Inspection of records or documentsInspection records or documents refer to the CPA's examination of records or documents generated internally or externally by the auditee in the form of paper, electronic or other media. The purpose of checking records or documents is to verify the information contained or should be included in financial statements.(2) Inspection of tangible assetsExamination of tangible assets refers to the CPA's examination of assets in kind. The procedures for inspecting tangible assets are mainly applicable to inventory and cash, as well as to securities, notes receivable and fixed assets. Examination of tangible assets can provide reliable audit evidence for its existence, but not necessarily for rights and obligations or valuation.(3) ObservationObservation refers to the procedure in which CPAs inspect the activities or execution of relevant personnel. For example, observe inventory counts or control activities performed by customers.The audit evidence provided by the observation is limited to the time when the observation occurs, and when the relevant personnel are known to be observed, the relevant personnel may engage in activities or carry out procedures different from their daily practice, which will affect the CPA's understanding of the real situation. Therefore, it is necessary for CPAs to obtain other types of evidence.(4) InquiryQuestioning refers to the process in which a CPA obtains financial and non-financial information from the internal or external personnel of the audited unit in written or oral form and evaluates the response. The inquiry itself is not enough to discover major misstatements at the level of identification, nor to test the effectiveness of internal control. CPAs should also implement other audit procedures to obtain adequate and appropriate audit evidence.(5) CorrespondenceLetter of credit refers to the process of obtaining and evaluating audit evidence by means of statements directly from third parties on relevant information and existing status in order to obtain information affecting financial statements or related disclosures. For example, letters of credit for the balance of accounts receivable or bank deposits. The reliability of evidence obtained by correspondence is high, so correspondence is an important procedure which is highly valued and often used.(6) RecalculationRecalculation means that the CPA checks the accuracy of data calculation in records or documents manually or using computer-aided auditing technology. Recalculation usually includes calculating the total amount of sales invoices and inventories, adding up the total journal and detailed accounts, checking the calculation of depreciation and prepaid expenses, checking the calculation of taxable amounts, etc.(7) Re-executionRe-execution refers to the process or control that CPAs re-execute independently as an integral part of the internal control of the audited unit by means of manual or computer-aided auditing technology. For example, the CPA uses the bank deposit journal and bank statement of the audited unit to reconstruct the bank deposit balance reconciliation table, and compares it with the bank deposit balance reconciliation table prepared by the audited unit.(8) Analytical ProcedureAnalytical procedures refer to the CPA's evaluation of financial information by studying the internal relationship between different financial data and between financial data and non-financial data. The analysis procedure also includes fluctuations and relationships identified by the survey that are inconsistent with other relevant information or seriously deviated from expected data.

What should we pay attention to in the process of container loading?

In the process of container loading, there are always some matters needing attention of shippers. These matters are not very important in themselves, but if we can pay attention to them, they may be of great help to the shipper's work. Today, Xiaobian will tidy up for you, container loading process, cargo owners need to pay attention to what matters.1. After the container is towed, first of all, the integrity of the container should be checked to see if there is any damage in the container, and check the box number with the box paper to ensure that the box number is correct. At the same time, the shipper also needs to keep the lead seal and record the specific lead seal.2. When calculating the packing plan, we should pay attention to the fact that each corner of the upper left/upper right corner of the container has a projection, so we should leave about 10x10x15CM space for loading.3. Cartons are not standard parts. Before packing, it is necessary to measure its length, width and height. We can not simply listen to the original data from the carton factory. In many cases, the cardboard boxes with cargo will bulge slightly in the middle, so it is more correct to keep about two centimeters of space around the inside of the container when calculating the volume.4. It is better to pack the new plan along the side line first to ensure that the length, width and height are suitable, and then to fill it compactly.5. When packing, especially at the beginning, the goods must be compacted as closely as possible. In principle, it is preferable to deliver the goods in the final comparisons while packing, but also to ensure tightness at the beginning of packing.6. Cartons are usually elastic and will naturally become denser after stacking. Therefore, before packing, we should first communicate with the loading and unloading foreman to give him a general idea of the packing plan. But we should not slacken off and delegate the packing to the workers. You know, when people do manual work, they are not able to use their brains soberly, so they should pay attention to the supervision of the goods beside them.7. Don't accept the porter's suggestions unless it's obvious. This is mainly because in many cases, these suggestions are based on labor saving and convenience rather than packing as reasonably as possible. Keep in mind that when something goes wrong in the packing process, the responsibility is also on the cargo owner, not on the loading and unloading workers.8. Short and medium nylon stockings with silica gel particles are a cost-saving and effective moistureproof method, and will not occupy space. A 20-foot container will lose four or five bags.Above are some matters needing attention when packing containers. In order to successfully complete container packing, we must understand these matters, so as to avoid unnecessary problems in cargo transportation and ensure the normal transport of cargo owners.