Interested in learning more about the automated testing process and procedures we follow here at NeuronicWorks for both high volume and low volume production? A member of our team will be happy to help explain.
Benefits of Automated Testing for Low Volume Production
What is Production Line Testing?
Production line testing involves the verification of a product’s functionality on the assembly line before the final unit is assembled. When a product is approved for production, the Quality Control (QC) team creates a test plan consisting of test cases, sequences, and procedures to evaluate the product’s functionality. The test plan may include a combination of hardware (HW), firmware (FW), and software (SW) tests to accomplish this. Test procedures are evaluated, modified (if necessary) then approved for production. Depending on the complexity of a product, individual components or sub assemblies may be tested independently before they are assembled into the final product. No matter how big or small the volume is, production line testing is a crucial part of the Quality Control (QC) process.
What is Manual Testing? What is Automated Testing?
For example, let’s say the unit under test is a PCBA. The QC team prepares a three-stage test plan consisting of a visual inspection, hardware testing, and firmware testing. Each stage will have a unique testing procedure and pass/fail criteria. If the PCBA fails at any point during testing, the failure will be documented, and the board will be put aside for investigation. At stage one, the operator performs a visual test to ensure that the PCBA has no scratches or deformities, all electrical components are present, aligned, and in the correct orientation, and all through hole components are soldered adequately. At stage two, the operator performs a hardware test to validate major electrical components. To accomplish this the operator will provide power to the PCBA and measure voltages and/or current values at test points across the board. Each value measured will be compared to an acceptable range outlined by the test procedure, the PCBA will fail if any measured value falls outside of it’s specified range. At stage three, the operator will upload the production firmware to the PCBA and verify that it has been uploaded successfully. The test criteria may include verification of the start up procedure, the execution of several test commands, and the shutdown procedure.
What is Automated Testing? What are its benefits for low volume production?
Automated testing seeks to automate most, if not all, of the manual testing procedures using Artificial Intelligence (AI), computer vision systems, scripting, or robotics. There is no questioning the value of automated testing for high volume production but what about for low volume production? When creating a test plan for low volume production (50 to 1000 units), it can be hard to justify the investment of time and resources required to implement automated testing. Here are 10 benefits of automated testing for low volume production:
1. Increased Accuracy
Naturally, manual testing introduces human error to the production process. Test accuracy refers to the test’s ability to correctly identify a pass or fail. An accurate test will have little to no false negatives or false positives. The accuracy of the test will depend on the test parameters and the test operator’s ability to execute the test steps correctly and record the results accurately each time. Automated testing allows for increased accuracy since the procedure can be scripted and the test can be repeated indefinitely without the risk of operator fatigue impacting the results.
2. Consistent Results
The preciseness of a test depends on its ability to reproduce the same results every time. The results of a precise test will have minimal random variation. With manual testing the precision of a test will rely on the operator’s ability to execute the test procedure and record the results with a high degree of precision. Automated testing ensures that every unit is tested under the same conditions with less risk of human error. For example, a test jig can be calibrated to send commands, measure multiple electric signals, and record values with the same level of precision every time.
3. Improved Scalability
When most of the testing is manual, it can be difficult to transition to automated testing if you decide to increase the production volume of your product. Automating testing for low volume production helps pave the way of increased production in the future. More specifically, low volume test automation will provide the development team with insight into potential roadblocks or pitfalls to consider when testing is increased for high volume production.
4. Free Up Human Resources
When testing is automated, less time is required for drafting procedural documentation and training, which significantly reduces the strain on human resources. Additionally automated testing is faster, requires less supervision, and does not require specially trained test operators.
5. Increased Test Coverage and Complexity
Complex products with a lot of components require more testing, and as a result, more time, and test operators. The coverage of a test cycle can be increased without sacrificing time by using automated test methods. Additionally, the complexity of a test can be increased without requiring the test operator to have extensive knowledge of the product’s functionality.
6. Improved Traceability
When testing a product manually, documenting the results can be time consuming. When testing automatically, test results can easily be recorded and uploaded directly to a database. In addition to test results, the database can include the date and time of the test, the name of the test operator, and a summary of the test environment (hardware, firmware, software, etc.) without relying on a tedious documentation process.
When a product is approved for production, various quality control methods are used to evaluate the product’s functionality on the assembly line. When testing a product manually the test procedure may become too complex or time consuming to be feasible. When testing automatically, scripts and test cases developed during the initial QA process can be reused and modified for use during production testing.
8. Identify Issues Quickly
First Time Yield (FTY) is the percentage of times that a product passes through a process without any defects on the first attempt. As the volume of a production cycle decreases the importance of a high FTY increases drastically. A low FTY in the initial stages of production can signal an issue along the production line. If many issues are identified in these stages, production can be paused temporarily to investigate them before investing a significant amount of money or resources into further production. The precision of automated testing accompanied by adequate traceability and documentation eliminates many variables associated with manual testing. Consequently, issues can be identified, and fixes can be validated faster.
9. Increased Flexibility
It is common for the development team to make changes to the production process during the initial stages of the production cycle. With manual testing, changes to the test procedure may require additional training, and supervision while the changes are implemented. When testing is automated, individual test cases can easily be added or removed from the test plan as the product develops with minor impact to the flow of production.
10. Improved Efficiency
Efficiency is critical for low volume prototypes with short lead times. All the above points combined allow for increased efficiency at every stage of testing without sacrificing quality. Increased accuracy and precision of testing will improve test quality, adequate documentation and traceability will aid the Quality Control team with quality control investigations, and the reuse of existing test cases will reduce the time required to develop a production test plan.