Sheet material binding apparatus and image forming system

An image forming system, comprising:

• an image forming section for forming an image on a sheet material;
• a binding mechanism for binding a sheet material bundle formed of a plurality of the sheet materials fed from the image forming section;
• a shifting mechanism for shifting a position of the binding mechanism between:
• a first position, at which the binding mechanism stands by to bind the sheet material bundle fed from the image forming section;
• and
• a second position, at which the binding mechanism stands by to bind the sheet material bundle manually supplied from other than the image forming section;
• and
• a control section for controlling, when the image forming section is in a state of being incapable of feeding the sheet material to the binding mechanism, the shifting mechanism so as to shift the binding mechanism to the second position.