Iduction motor fault

[jAMEs12]

One of induction motor installed at our flour mill plant was failed to start. we first check its automation circuit powered through siemens s 700. we checked wiring, incoming signal, plc relays all was seem ok but still there was some problem because motor did'nt start by input signal. Then we go for mcc panel and tested its switching relay by this method. I.m a bit confused about this, can someone suggest me some more methods to test relays and plc system entirely.