Good books on testing of just developed device - Page 1
Forum section: electronics / testgear

author: MrYakimovYA
author_rank: Regular Contributor
timestamp: February 10, 2017, 01:50:49 am
content: Hello, everyone! Sorry if I ask my question in wrong topic, I'm new hereI search some books describe the process of testing developing hardware (analog and digital circuits, maybe software that controls it). For example, we have just developed new DMM. It has a lot of hardware solutions and software thingsAs the product is new one we need some tests that must be done to decide what to do next: throw it away and redisign or sell it.Of course, I understand that we can test it from user view: press buttons, connect it to different voltage, current references and so on. But I want to formalize the procedure, take some scientific approach. To do it I need books... So I've come here to ask you help mePlease, point me to some good books that clarify testing routines, that tell me how to build them in a right way

author: joeqsmith
author_rank: Super Contributor
timestamp: February 10, 2017, 04:35:50 am
content: Seems like an alright area to post it. I would be interested in books on this subject myself.

author: tggzzz
author_rank: Super Contributor
timestamp: February 10, 2017, 09:09:38 am
content: There's an argument that it is already too late, since a product should be designed to be tested. "Design for test" or DFT might be a useful search key

author: nctnico
author_rank: Super Contributor
timestamp: February 10, 2017, 10:57:59 am
content: Quote from: tggzzz on February 10, 2017, 09:09:38 amThat is a good point. When designing a circuit I like it to be able to test itself and if that is not possible it should be easy to test (special test mode, connector to hook up test equipment, etc).For testing a product with buttons, display and so on I have good experience using a test plan which guides the tester through all the necessary tests and also collects data on the test results. In many test equipment service manuals you find similar test plans which usually are in the 'performance verification' section.

author: ebastler
author_rank: Super Contributor
timestamp: February 10, 2017, 11:07:52 am
content: Quote from: tggzzz on February 10, 2017, 09:09:38 amIn my understanding, DFT focuses on designing the product for production tests, i.e. testing each unit for correct function before it gets shipped, to catchproductionflaws. In contrast, the OP seems to be after test approaches for a newlydesignedproduct, i.e. testing the prototype for weaknesses in the design. (MrYakimovYA, did I get that right?)In that case, FMEA (failure mode effect analysis) is a good search term and starting point: You should start with a systematic analysis of what could go wrong in your product, and how the design tolerates, compensates, or at least indicates critical problems. E.g. think about effects of temperature drift, robustness against excessive voltages or wrong connections, robustness against electromagnetic immissions etc.. Once you have identified potential critical impacts and failures, that will inform the design of your testing program.

author: tggzzz
author_rank: Super Contributor
timestamp: February 10, 2017, 01:48:16 pm
content: Quote from: ebastler on February 10, 2017, 11:07:52 amJust so, but there is significant overlap in the mental thought processes, and in the practical details. It isn't completely clear to me whether the OP is after design tests or production tests.If they've thrown something together and are only now wondering whether it works, well.... good luck to them.There's an old engineering axiom that is ignored by the XP/TDD brigade: "you can't test quality into a product".

author: MrYakimovYA
author_rank: Regular Contributor
timestamp: February 10, 2017, 02:02:26 pm
content: Quote from: tggzzz on February 10, 2017, 09:09:38 amFor "DFT" thank you!What about "it is too late" I can say that the DMM was just for example)))

author: MrYakimovYA
author_rank: Regular Contributor
timestamp: February 10, 2017, 02:07:03 pm
content: Quote from: nctnico on February 10, 2017, 10:57:59 amI suppose HP manuals are good starting point!

author: MrYakimovYA
author_rank: Regular Contributor
timestamp: February 10, 2017, 02:18:16 pm
content: Quote from: ebastler on February 10, 2017, 11:07:52 amYes, you are right! But DFT is also applicable for meI collect information now, and any sort of topics may help me. I'm interested in how to test the prototypes for faults and weakness. I also would know what I should do for new designs to simplify testing.

author: MrYakimovYA
author_rank: Regular Contributor
timestamp: February 10, 2017, 02:21:09 pm
content: Quote from: tggzzz on February 10, 2017, 01:48:16 pmBothAs I mentioned earlier I want to cover as much information on testing as I canSo I need books, if such books are real... may be there are no book on this topic?

author: nctnico
author_rank: Super Contributor
timestamp: February 10, 2017, 06:27:54 pm
content: Suddenly I recalled a buzzword: TMAP and it turns out there is a Wikipedia page about it:https://en.wikipedia.org/wiki/Test_Management_Approach

author: 2N3055
author_rank: Super Contributor
timestamp: February 10, 2017, 09:15:37 pm
content: Well, if you want to take a look at formal treatment of product development, for instance you can take a peek at :https://www.crcpress.com/Design-of-Electromechanical-Products-A-Systems-Approach/Jamnia/p/book/9781498742191And more directly to your question, it's not about testing. It is about verifying whether the product you're developing conforms to:1. Requirements as defined by customer.2. Regulatory and/or any other legal requirements for that product to be used and sold.So it goes like this (very simplified):1. In talking with customer you freeze specification of what product does and with what quality. That includes environmental requirements, accuracy and all such technical specs.2. Then you make technical analysis and come up with technical solution that can achieve those specs.3. Optimize for cost and/or other requirements4. After roughly having technical solution defined, you devise test plan how to test your technical solution against specs in point 1.and 2.That includes adding test points and test code to the prototype to be able to execute test plan.5. Make prototype.6. Test.7. Make notes what was wrong.8. Rinse and repeat.. Until it works as it should..Regards,Sinisa

author: metrologist
author_rank: Super Contributor
timestamp: February 10, 2017, 09:24:36 pm
content: Are you interested in product reliability or usability?We use halt/hass testing methods for the former, customer surveys for the latter (just kidding)

author: tggzzz
author_rank: Super Contributor
timestamp: February 10, 2017, 09:28:30 pm
content: Of course, both your points numbered "1" can be problematic. That leads to agile development and TDD - which are definitely beneficialin some circumstances. But of course, "you can't test quality into a design".Anybody that thinks you can simply follow a process to get a good result is either a fool or has something to sell.You have tothinkand use mature experience.

author: 2N3055
author_rank: Super Contributor
timestamp: February 10, 2017, 09:48:07 pm
content: Quote from: tggzzz on February 10, 2017, 09:28:30 pmWell, I said greatly simplified...Critical is that, while you are talking to the customer, you don't let them go crazy with things that cannot be done..And that you FREEZE requirements at one point..And have that in writing, in a contract.That part shouldn't be negotiable afterwards...And you should design in the test facilities in the prototype.. At that point, experience is king...I agree, there is no magical process that will, by definition, spit out good products..Trick is to give yourself enough tools to be able to develop product that was ordered.And to answer directly to OP, no there is no book that will tell you how to test every product...In a design phase, you have to make a list what needs to be tested to prove product is as it should be..And all starts with product specification, intended use and market and such..

author: tggzzz
author_rank: Super Contributor
timestamp: February 10, 2017, 10:42:20 pm
content: Quote from: 2N3055 on February 10, 2017, 09:48:07 pmYes.QuoteOften the customer doesn't know what they want at the outset; frequently requirements emerge during the design. That has to be catered factored into the process.QuoteMost definitely.And you should also implement, test and prove each part independently of the others, in a logical sequence.QuoteYes, with the caveat above.If you don't have a specification, thenanythingwill meet it!

author: MrYakimovYA
author_rank: Regular Contributor
timestamp: February 13, 2017, 01:38:19 am
content: OK... thanks for your replies, gentlemen!!! They clarify a lot for me.