Today, it was very interesting to learn about why companies conduct product testing. Mostly for the reason for, how the product is going to operate, maintenance costs, how reliable it’s going to be, how customers’ requirements are met, government regulations are being met attached to certain industries. For instance, design reducing emission levels to reduce pollution in the UK for the vehicles. Another interesting information in the same context was getting to know about a policy in the UK about MOT safety check like every 3 years has to be taken to the garage for checking, wheels, engine, and seat belt safety and suitable to operating ensuring that safety standards are being met.
I learned so many types of product testing used in different industries. For instance another type is REL growth testing is done during, when the product evolves over a period of time and life cycle, and to check if its meeting customer reliability requirements. It tests cause of failures during design period, identify what the failure and stress levels are which cause the failure. It is much more cost and time efficient. Used mostly for testing some critical parts of air-craft. From the example of Train crash video we saw in the class today, high costs were involved for introducing air suspension so they went with the cheaper solution of introducing rubber technology in the wheels for the added comfort and smooth journey, but without putting them through any testing phase and only approved by the management. So no idea of the stress levels and fatigue was gauges resulting into the catastrophe.
Another type of testing we learnt today was ALT Accelerated life testing: where you increase the usage rate during testing to the max. For instance increase in the number of revolvation during testing a train wheel on a testing system ( from the train crash video today). Over stress testing put the product in extreme environments like temp or speed or stress. Constant stress is when product is put to constant stresses during testing by controlling the environment like temperature or acceleration. Step stress testing like stats at 40 degree than 5 degree up and then after some time stepping up to 50 degree, assessing failure level at different levels, and what can be done to eradicate such failures, probability plot can be used for this kind of testing.