In this thesis results from the existing test machines that Fresenius Kabi AB, Uppsala, uses today have been compared with the complaints that the customers returns to the company. By this the differences between the damages and holes on the outer pouches of the bags could be found. Two different machines have been used: the shaking table and Gelbo Flex tester. The holes on the pouches were located by filling them with air and put them in water and look for bubbles. A microscope was used to find the reasons behind the wear. The dominating types of wear were creep, abrasive wear and fatigue wear and temperature increase makes the bag even more sensitive for any type of wear. A new type of equipment was built to be able to test the pouches on the shaking table without friction heat. These tests showed much better results that looked more like the complaints. To reduce the number of holes, new designs on the outer pouches were tested. A better design was found by using tables and PUGH-matrix, but some holes were still there. Therefore some calculations were made to get more realistic parameters so the tests got the same severity as a real transport. Some of the parameters were tested to find the ones that get results most similar to a real transport. The new design was then compared with the old one, to see if the difference was big enough to say that the new design is better even in this test. The results showed clearly that the new design was better