Which one of the following is not among the standard process chart symbols ?

1. Operation: An operation is an action performed for advancing towards desired result. This indicates the main steps in a process, method or procedure.
2.Inspection: An inspection occurs when the product is removed for a time for production. It includes the visual observations for finish, checking the dimensions etc.
3.Storage: A storing occurs when the product is removed for a time from production. For example, materials kept in stores to be distributed to various work.
4.Delay: A delay occurs when some undesirable event prevents or hinders the next planned activity e.g. waiting for a machine to be repaired. A traffic jam. Work waiting between consecutive operations.
5. Transport : A transport occurs when there is movement from one place to another. It indicates the movement of materials from one work station to another.