Fabric structures are often referred to as tensile structures which refers to the basic principles involved i.e. the fabric system should be in tension.
Poor design can result in asymmetric tension forces which can lead to bending as can be seen in the above photo. The tensioning thread in this example is above the line of the edge cables which causes the thread to be placed in bending. The will result in premature failure as these devices are not designed to be placed in bending.